Not a great time price-wise to be building a NAS, but I have been doing so for the last two weeks. Inside a Jonsbo N6 case, which is pretty nice with an 8x SATA backplane and drive bays (unlike the earlier Jonsbo variants).
I ended up on shucking 4x the 14 TB WD Elements Desktop. They contain helium drives, the WD140EDGZ in my case, and are about a third cheaper than 4x the 12 TB WD Red Plus drives (which are air-filled). The shucking was easier than I expected too, and the performance seems very comparable. The warranty is a definite downside (European, so no Magnuson-Moss), but I think I can even get them back in their enclosure should they fail during the 2-year warranty period.
I've put some second hand 256 GB M.2 SSDs in there as boot drives. It was a bit of a struggle to get it to work in a way that failure of one of the drives doesn't hold up booting, combined with LUKS, TPM keys and ZFS on root. Learned a lot about systemd-boot which I have never used before, but feels a lot saner to me than grub ever was. So now I have a large script which debootstraps a Debian based NAS into being.
I noticed that there are a lot of ZFS myths and cargo culting. For example TFA mentions ECC RAM, which in some circles is a must-have because ZFS would wreck your pool during a scrub otherwise, which is a myth. It's also very expensive, especially this year. You also don't need much RAM for ZFS, L2ARC doesn't use much RAM at all, to name a few others.
Still doubting about setting `dnodesize=auto` (which is the default), because there are some horror stories about that [1]. And it seems impossible to find a cloud storage provider with reasonable prices that supports `zfs send`. Rsync.net upped their minimum order to 10 TiB recently, which is far too much for my use case.
It was €329 per hard drive (through a reputable store), and I chose the ASRock B650M-HDV/M.2 mATX motherboard combined with a Ryzen 5 8500G. Stock CPU cooler, replaced the Jonsbo case fans with Arctic P12 Pro PST LN. I only slightly regret the PSU (MSI MAG A650GL), which could be quieter. Not that it's very noisy, and it's a great PSU otherwise, but I should've chosen one that just shuts the fan down at low power usage.
You have SATA or SAS to pick from. The CPU requirements for a storage server are not high. On a typical ATX board you have motherboard SATA and can put SAS controllers in the spare PCIe slots.
My first "NAS" was two 22TB hard drives in a ZFS pool on my motherboard SATA
> Not a great time price-wise to be building a NAS
That under-states the matter. It is a terrible time, price-wise, to build a NAS.
I'd almost rather have no AI whatsoever and have storage 1/10 the price of pre-AI times.
(If there were a magical choice between having AI and significantly more expensive storage, and having no AI and some program to dump that investment money into getting and somehow leveraging significantly more available storage, that is.)
I would kill (figuratively, anyway) to have no AI whatsoever. No slop machine threatening to replace my job, or turn my job into babysitting its stupidity, and hardware would be reasonably priced? That would be awesome. AI has brought me nothing but downside.
I immigrated wanting to become a millionaire. Never found time working my ass off. Now that I get pension and tokens from Musk and Zuck, I can finally try!
AI has freed most people I know from the tedious job of writing actual emails and birthday greetings - leaving then more time to e.g. wash dishes or clean the floor.
Seriously, if arts and creativity is what sets humans apart from other animals, then AI has almost completely displaced our capacity to even consider doing these activities ourselves. People reach for AI when they should be composing a birthday greeting themselves.
Was it a genuine birthday greeting when you bought a card? Or used an online card? I don’t really see the difference. The point is you thought of them, not the actual words
Great business opportunity there. Make a free service that sends AI generated birthday notes to people. All the user has to provide is the other persons birthday.
People cannot be relied upon to provide accurate birthdays but nobody would suffer the social faux pas of an incorrect birthday congrats note. Nor would they send it to a spam catching email, but rather are guaranteed to send it to a regularly checked address. They know the persons birthday after all.
You can then sell high quality birthday information correlated to contact information to ad agencies.
and i would kill (literally) every billionaire and every politician in the world to make sure everyone has full access to ai. every time it helps me with code or skipping the boring parts of college or just a random question i think about the billions of people who cant because they live in a poor country or just dont know how to use it.
ai gives people incredible power so it needs to be shared equally, not locked up and controlled. the only ones threatening to replace jobs are capitalism brained humans (or maybe they already lost their humanity way before chatgpt) who want profit at all costs and believe machines can replace people even if theres no evidence. fight the system not the tech.
I'm also planning a new home server build now and the prices are definitely relatively ass. So far I've spent 820€ on two 22 TB WD Elements HDDs, 375€ on 2x16 GB DDR5 kit, and 520€ on two 2 TB M.2 SSDs (cache). About 1700€ and I still have no server to show for it. Doesn't help that I've been procrastinating on picking the CPU and motherboard.
I’m running an 8-drive ZFS RAIDZ2 pool. I’m wondering if you know — are the free space recommendations around ZFS cargo or real?
Like I’m already giving up two full drives for redundancy (which saved my ass - I recently had two drives fail on me in quick succession — both SSDs from what looks like an identical batch) but then the advice is kinda saying I need to keep at least another drive worth of space free for the pool to perform well and not crap itself. That hurts with current prices for sure.
ZFS will auto-degrade performance if there isn't enough headroom. In addition, if you use SSD, you also want the headroom, because otherwise you end up writing and rewriting on the same small empty space which kills SSD (unless you have enterprise SSD, which have built-in headroom).
Not sure why I'm being downvoted for being factually correct (and also, why I can't edit my above comment).
ZFS will definitely degrade write performance gradually from 90% utilization, and will hit a stronger cliff at 95%+. Same with SSD, using a consumer SSD above 90%+ utilization would rapidly degrade its lifetime. The effect will be smaller for very large pools and very large files, but the effect is stil there.
I'm repeating this so that people who set up these drives know what is actually going to happen.
I appreciate the reply, but my warning consumer SSD is not incorrect. While they typically have a small overprovisioning of 7%, enterprise SSDs have close to 4 times as much, exactly to allow more writes (which is very relevant if running a ZFS raid on the drive). Keeping 10-20% headroom will prolong your SSD's life significantly, and increase performance of ZFS.
> I’m running an 8-drive ZFS RAIDZ2 pool. I’m wondering if you know — are the free space recommendations around ZFS cargo or real?
I'm not entirely sure, but it seems to me that free space (and the 20% reservation) is mostly a proxy for fragmentation, and you can therefore better look at fragmentation directly. That would mean that if you mostly store large files, there shouldn't be a lot of fragmentation even at high utilization. The whole "ZFS changes allocation algorithm from 80% usage on" is something of 10+ years distant past, and lots of things around the allocator have been improved. It's also something that probably isn't too different from the performance of other filesystems at high utilization, so it shouldn't be exaggerated.
For home usage, if you have backups raidz1 is fine (just do an incremental backup at the first sign of trouble). If you don’t have backups, then you probably shouldn’t be running a NAS in the first place.
I recommend staying away from SATA drives (huge consumer rush) and look for SAS drives on eBay, particularly HC520 Helium drives from HGST/WD. Need a SAS3008 PCIe adapter ($20) and a SFF-8643 splitter ($30). No backplane is required. Huge lots of decommissioned drives frequently appear. I bought Qty 10* of HC520 (12TB) SAS drives for $1000 about 3 weeks ago, avg age is about 2.5 years, still well within its rated lifetime.
Yea may be some of the stuff is fear mongering and cargo culting. I was told ECC is necessary for ZFS. When the article was written, it was cheap af (2024) to buy ECC RAM so not much consideration was given to it.
--
(*) I have no idea what to do with it. Anyone has any good idea for using 120TB space? I have about 40TB unused bandwidth in the datacenter, may be host a Debian mirror? Donate storage/bandwidth to Internet Archive? Please contact me, appreciate it.
> I bought Qty 10* of HC520 (12TB) SAS drives for $1000 about 3 weeks ago, avg age is about 2.5 years, still well within its rated lifetime.
That's cheap indeed. Enough headroom for some failing disks too. How is the noise and power usage? I didn't look at SAS drives at all, because my impression was that they're very noisy. I can place my NAS in a closed off room, but it's not too far away and I was afraid SAS drives would be audible through the wall. At the same time, the shucked drive I'm using presents itself as an WD Ultrastar, which comes very close to a SAS drive, and isn't very noisy.
You assert that ECC RAM being necessary for ZFS is just a myth but provide no justification for why that is untrue.
Is it not the case that if you don't have ECC memory, ZFS could end up writing a checksum that does not match the data if you get a bitflip in just the right (wrong) spot?
Yes, indeed. ECC RAM is better than non-ECC RAM, also for ZFS.
The myth, popularized by a notorious thread on the TrueNAS forums [1], is specifically that ZFS requires ECC RAM, and will do worse than other filesystems without it, because scrubbing will multiply a single bitflip into a failed pool.
A ZFS core developer says that that isn't the case [2]. Here's some more reasoning [3], also about many other myths.
Usually if you’re using a NAS you don’t want to lose data, ZFS is not significantly more sensitive than everything else.
But everything is actually quite sensitive.
We’ve accepted lack of ECC because Intel decided it would be a product line differentiator, and serious customers who didn’t want random crashes or to lose data would buy chips with ECC.
It’s actually less of an issue these days because DDR5 has (by spec) some in-line ECC; won’t help with multi-bit errors but its an improvement on what came before.
I know that LPDDR5 has ECC, and not just single bit AFAIK, but if you enable it you lose some memory capacity (the 128 bit bus minus 16 bit for ECC error correction, making it effectively 112 bits)
The only hangup with the myth "debunking" is that the point is that the corruption doesn't happen to a per-disk buffer, but to the in-flight data before it's persisted to your stripe.
Which means all copies of the data will be corrupted. This can be anything from an irrecoverable file to complete filesystem corruption.
But generally, yeah, not any more dangerous than any other filesystem, and ECC used to be cheap so it was a no-brainer, you should have backups anyway TBH if we're being honest about storage resiliency.
What has been debunked is the "scrub of death" issue, on a scrub a bad bit flip would cause an error, which would be copied over with good data -- well it was technically good before. It would be statistically difficult to have a fault on a read, then a clean read, then a second bit flip destroying the data.
If you are worried about someone breaking in to your house and replacing the bootloader while leaving your drives in place I probably wouldn't use the TPM auto unlock even if in theory secure boot should be able to handle this.
But in reality that will never happen and the only actual attack you need to be worried about is junkies breaking in and flogging the drives on facebook marketplace. For which, this level of security is fine.
Install avahi-daemon. Samba will automatically register with it to advertise SMB/CIFS to macOS and Linux clients over DNS-SD.
Install wsdd2 so that your server will be auto-discovered by Explorer on Windows 10+ clients with SMB 1.0 disabled, too.
Your Linux hostname is probably lower-case, but by default, Samba publishes a capitalized rendering of the hostname to NetBIOS and Avahi. If this bothers you, set “host-name=something” in the [server] section of /etc/avahi/avahi-daemon.conf, and set “mdns name = mdns” in the [global] section of /etc/samba/smb.conf.
If you have macOS clients, you should enable vfs_fruit in your Samba configuration: https://www.samba.org/samba/docs/current/man-html/vfs_fruit..... There are some compatibility reasons to do this, but mostly it means you can set the “fruit:model” so that your server has a fun icon in the Finder sidebar.
Although macOS deprecated AFP in favour of SMB years ago (and are slated to remove AFP client support altogether in the upcoming macOS 27), SMB client support in macOS is still pretty miserable. The upcoming macOS 27 is set to drop AFP support, but until then I will continue to run Netatalk side-by-side with Samba. Netatalk also registers itself with Avahi, and macOS will (tellingly) use AFP preferentially to SMB, so clients will talk to the right daemon automatically.
I think it's appropriate to link to my blog post about building such a NAS but with very different technologies: dm-integrity, mdadm and XFS. The reason being that as a C/C++ dev following OpenZFS development closely, I found the focus on ginormous features over general stability and the constant problems due to the SPL/separate page cache too worrying.
Sure, I traded the convenience of kitchen sink (or Swiss army knife for the more charitable souls) ZFS for some initial pain, but I'm very happy with my choice today.
I still pay for snooty, and the reason for that is that when a disk goes bad (not if; when) I pop its tray out, replace the disk, pop the tray with the disk back in, click a couple of widgets, and that’s it. I know it will be rebuilt properly.
(And I know I have to do that, because when the disk fails it beeps and lights a led near the bad disk)
It’s easy to build a NAS such as the one described in this article, but in the long run, data loss is significantly more likely.
Also, any guide like this that doesn’t guide you through “disk 3 failed, this is how you safely replace it” is imho incomplete, even if it doesn’t go through telling you how you know a disk has failed.
That is kind of exactly how zfs works though. The guide isn't complete, sure, but "rebuilding" the array is just replace the disk and run a single zfs command.
That’s comforting to know; that wasn’t true in the past for ext4 over lvm (is it true now?).
But what is that command? And how do you know which disk has gone bad?
I am sure I can get an answer from Google / Claude / ChatGPT, but a guide is incomplete without it - and the failure report should be active like a beep or flashing hardware light - I typically log into my NAS only a few times a year. A motd or other banner isn’t sufficient.
I used to look after storage arrays for VFX places.
everytime I saw lvm I inwardly sighed. The docs were terrible, almost as bad as MDADM. snapshots were for a long time unrecoverable. You'd then have to work out what pattern of LV you had, was it a suprise raid0? or a misaligned raid1?
zfs is a night and day compared to LVM/mdadm, two tools, rich help, the man pages are reasonably good, and once you understand zfs vs zpool, you're usually good to go.
To be fair, the "beeps and lights a led" part is very important in case of a dead disk in an array. The only time, I disrupted a service in production for longer than a few hours was when I didn't get the email of a degraded raid 1 array and the second disk died a few weeks later.
Same, using NixOS as a NAS, though it kept growing and now I'm trying to share it with other people. I use BTRFS on MDADM though. It's ended up being an all-in-one home server and router now because I was tired of the noisy power hungry rack I had in my closet.
I found cockpit to be incredibly useful for managing NAS and VPS. Even though any configuration is not an issue with LLMs, having a dashboard with toggles, formatted logs and such is helpful, and I can even run shell commands on phone without ssh. In the NAS case, you can easily see the results of backup/maintenance cronjobs, manage samba (which is a huge pain in the ass to get to work properly on iPhone), and monitor disk usage
I'm sure people have reasons for taking these things as far as they do with ZFS, and everything else that goes into what is commonly considered a "NAS." But I've found great convenience in a tight NFSv3 config running from a single high capacity HDD with ext4 on a Linux machine (primary system that's always on anyway while I'm around/awake) making things available to my other devices for the electricity and overhead cost of one machine instead of multiple.
I try to keep my network configuration restrictive by default, so I'm not too concerned about possible security arguments running it from my main machine. I've probably committed some great sin here, but is plain NFSv3 and secondarily Samba (for compatibility) really not enough?
First: Do you have backups of your single high-capacity HDD? That's my biggest worry. What's your plan for when that HDD fails one day, as it will?
The main reasons people go for ZFS and a "NAS" is checksums and data integrity protection, as well as maybe not wanting to keep their primary machine awake all the time (I personally don't).
Then there are useful features like snapshots, which means I don't have to worry as much about accidentally deleting, or over-writing a file and losing data.
I don't see anything wrong with using a main machine that's up 7x24 as a NAS, don't buy things for the sake of something, but I'm worried about your reliability and bitrot protection. (Yes, it happens, I've seen it first-hand thanks to ZFS).
I have external parity for everything with rsync. I don't have any storage that isn't matched with external backups. Fortunately I've never seen any bitrot or had a drive fail on me since I tend to replace them before they do. And yeah, I could add in some extra HDDs for RAID, but this is more a personal choice because of how much I hate SATA.
Filesystems like ext4 are because I value boring and rock solid stability over semi-experimental status of modern filesystems with all the features.
It's more the single drive storage layout that is an issue in your case. No resilience to a single disk failing and you are risking all your data if your hardware starts silently corrupting data. This is assuming all your backups are done using the data on the single hard drive.
If you want to keep your setup simple I would consider the following:
- Keep a list of file hashes and check your files against this list periodically.
- Use some type of backup program that supports snapshots. Restic is a good choice.
- Get a hard drive the same size as the one you have and use SnapRAID to manage file integrity or set up a two disk mirror using btrfs.
Building a NAS from scratch is really fun! A small hinderance, but definitely part of the fun as well, is the lack of a "complete resource" on the topic covering how to do every single thing you need to do. Part of the point of my blog post is actually to bring to the internet yet another opinionated NAS setup "guide" (eventhough I would hesitate to call it a guide, but if I ever had to do the same thing again I would definitely read my own post first).
I made 2 Raspberry Pi5 NAS's. one with 4x 6TB and one with 4x 12TB.
Used mergerfs and snapraid, and a simple NFS share. Absolutely perfect for Proxmox backups, our pictures, media, etc, etc. No fuss, easy replacement of drives without needing to keep drives of the same size around.
I'm good with ZFS, have been for years now managing storage for $COMPANY. And I still freaking love using zfs send/receive with proxmox ;-)
But for most at home stuff: mergerfs and snapraid are just more logical.
I really, do not want to have a big server rack lying around at my house. I have a couple of SSDs that are not being used and 3 USB HDD drives. I also have a PN50 that I am not using as well.
I am thinking of buying a USB bay with 5 SSD slots in it and then 3 HDD drive.
My use case is very, very cold. It is mostly just readonly data with some rclone sync every week.
Does anyone have a suggestion? I am pretty much relying on ZFS to do all the redundancy for me.
USB/SATA adapters are incredibly flaky. Some don't support TRIM, some have major firmware bugs, many overheat during long data transfers and disconnect from the host. I'd strongly advise against using them for any important data.
10 months ago I've built a Raspberry Pi 5 mini NAS with 3 SSDs connected through RADXA Penta Hat. It runs OpenMediaVault, system is on the SDcard, other data are on the SSD ZFS pool. I have autosnapshots enabled, and I tune compression methods on specific datasets (lz4 for almost everything, zstd for file backups).
We use it for storing (backups, media files), playing (PaperMC), and watching (Jellyfin). I can only complain about the lack of hardware decoding in Raspberry Pi 5. Jellyfin loads CPU much if I enable transcoding so it's always disabled. If I knew this, I'd consider a cheaper and faster, but less popular, RADXA machine. Storage is fast enough for me, rsync and Samba speeds are usually limited by my network. PaperMC also runs without a hitch, thanks for asking!
As I didn't have high requirements for the machine, I also considered USB Bays at first but they wouldn't go well with ZFS.
I'd probably just buy a cheap prebuilt PC with a big case, or surplus enterprise tower. You can get cheap LSI PCI cards and do miniSAS to SATA if needed.
The biggest concern I'd have with USB is power delivery to the hard drives, but I haven't even done the napkin math so maybe it's fine. The SSDs seem like they might be a waste of money. USB hard drives have a poor reputation, but I don't have a ton of experience to say how much of that is deserved. On a practical level, I'd also be concerned about knocking the cable out.
Just yesterday I was brainstorming with ChatGPT about this. I have an ancient QNAP plus a slightly less ancient NUC running PiHole, Wireguard and other services. Both need replaced, so why not combine them?
I don't know much about ZFS, but it sounds like I need to learn. Docker may have conquered the world, but I plan to stay with LXD for services.
The one thing I take issue with: an appliance like this runs 24/7. It should be low power and fanless. A processor like the N100 seems like the obvious choice.
> I am creating a RAIDZ1 (RAID 5) zpool. That means 1 drive redundancy in-case of failure
A friend once told me that RAID5 has a high latency cost, because every Write requires a Read to update the stripes across all drives, and while this made sense when drives were expensive, nowadays you might as well do a RAID10 instead, and trade space for latency.
RAIDZ1 will add more stress to the consumer ssd's as to enterprise one due to surprinsingly different hardware. Consumer ssd's life times are calculated on a 8 hour shift (the tbw) and enterprise are calculated on 24/7.
Please - dont - use - consumer ssd's - with zfs raidz1
It's complicated, but https://jro.io/capacity/ actually walks you though how it works, towards the middle of the page.
```
Unlike traditional RAID5 and RAID6 implementations, ZFS supports partial-stripe writes. This has a number of important advantages but also presents some implications for space calculation that we'll need to consider. Supporting partial stripe writes means that in our 7wZ2 vdev example, we can support a write of 12 total sectors even though 12 is not an even multiple of our stripe width (7). 12 is evenly divisible by +1 (3 in this case), so we don't even need any padding. We would have a single full stripe of 7 sectors (2 parity sectors plus 5 data sectors) followed by a partial stripe with 2 parity sectors and 3 data sectors. This will be important because even though we can support partial stripe writes, every stripe (including those partial stripes) need a full set of p parity sectors.
```
I've been thinking about setting up something like this for a while. I have a Broadwell dual socket Xeon workstation that I'm going to upgrade to Proxmox. Would it be reasonable to run something like this as an LXC or VM or would you put it in the base kernel?
One alternative for those who don't want any of the major NAS vendors, just use RHEL10. It's free up to 16 licenses, it's ultra stable, cockpit is a very mature gui for a lot of maintenance tasks.
It's a set and forget OS that will run for years without requiring your attention. But these days it has decent container support for hosting services on.
The problem with RHEL is that the free version exists at the sufferance of IBM, a company not well known for being motivated by keeping tech enthusiasts happy. I would use Debian, personally. Not as long of a support cycle as RHEL, but still quite stable and no possibility of corporate rug-pulls.
its probably dumb but what i do is use proxmox with a debian VM with docker installed and each docker container gets a virtual disk i make on the proxmox host. obviously more involved than running unraid or truenas but i think the complexity underneath is simpler.
Thats perfectly reasonable. Double isolation but that isn’t too costly.
I’m talking more about people doing the same as you except they’re linking the VM storage to another vm (truenas) over network despite it all being on same host. Think it’s mostly because people don’t want to deal with zfs via command line
To this day I still use a ZFS array for my critical backup storage. I've migrated over to using snap raid + mergerfs for my larger Linux iso storage array. Simple enough and I can pull a drive on it's own without any other stuff.
It's a horrible idea likely, but I have an ancient old Dell PowerEdge R510. Probably sucks way too much energy, but it does what it does and the price of SSDs have skyrocketed so I'm not touching it.
I'm sure there's better options now but the HP ProLiant MicroServers (used).
They support ECC ram, 4 caddies, one extra PCIe slot, and to my knowledge you're not cpu limited for a zfs file server usecase.
Keep in mind though, all you need is linux* support, iDRAC, ECC if you're a snob, and drive bays ... and that's basically any free server.
In my extremely opinionated opinion I would only get used enterprise server gear, because a zfs file server will just work unless hardware fails. And a UPS.
*ZFS will be a more natural choice on FreeBSD. It's better documented, and will meet Linux 1:1 in hardware compatibility for this.
I'm still running an old Gen 8 MicroServer. Modern drives can actually saturate the SATA controller, and because it only has a single PCIe slot I can't add both a 10Gb NIC and a storage controller - I went with the 10Gb NIC.
It works well enough though and has lasted me over a decade at this point. 16GB DDR3 ECC, an old 4 core/8 thread Xeon, 4x14TB drives and the Mellanox NIC.
Agreed. I have used a HP N40L ProLiant MicroServer since 2013 as home NAS and Time Machine backups via samba. Rock solid hardware, incredibly expandable, and today runs FreeBSD 15.1 with ZFS. Additional hardware modifications include; CD-ROM replaced by two 3.5" HDDs on mounts (now six HDDs of 10TB each in ZRAID1), a SAS card to add two mirrored bootable SSDs underneath CD-ROM drive space, a 2x 2.5G NIC (limited to 4GB/s slot) for dedicated NFS link, while additional internal SATA and external SATA ports unused. Next: replace PSU fan with quieter Noctua fan.
Not strictly a recommendation, but Terramaster is a good brand to look at if you want Synology-shaped hardware which can run TrueNAS or Proxmox or any flavour of Linux you want.
Along with various other devices (including a large Synology which I wouldn’t buy today), I run Proxmox on a small two bay+two nvme Terramaster. I have a bare bones Ubuntu LXC running Samba configured for Apple Time Machine, an VM running Scrypyed, and PBS for Proxmox backups. Nothing on it is critical so I don’t bother with any storage redundancy.
I have the F8 Plus, great little unit. It did need a BIOS update when I first got it to enable Proxmox/other OSes to work properly.
Recently replaced the internal USB boot drive with a small NVMe USB enclosure; using a 90-degree USB connector and using a dremel to sand away an opening for the cable to come out so I could mount the enclosure externally.
A friendly reminder since it's probably relevant: when's the last time you tested disaster recovery for your own setup? If you haven't verified recovering it, you don't have an offsite backup.
I had a cloud backup (Backblaze B2, using rclone and encryption) for my home NAS. Some unlucky drive failures later, I was getting ready to recover from my Backblaze backup... and then I couldn't find/remember where I saved the rclone encryption backup.
I lost all data in that NAS, including irreplaceable personal/family photos, due to that mistake. My lesson to share: please verify you can indeed recover from backups.
I killed 2x 4tb Nvme drives on Pciexpress with ZFS raid1 under proxmox, got them replaced, tried again on both pci-express and usb adapter kept getting io problems there too with zfs, drive gets disconnected during scrub or high load, tried already kernel or power management options for pciexpress and usb without sucess, managed to reproduce with high load.
or proxmox ( especially community edition) is fucked or zfs is still unstable, surprisingly with different drives on different interfaces I obtained same results, didnt swap proxmox for clean os, that might being some changes since modules and options would be different i guess. ( drives firmware etc are fine and performing well when inspected with proprietary windows tools)
just search zfs nvme pcie or usb problema or disconnect and you see similar stability problem for different users in different cases (os, drives etc), but also unraid and others, maybe somewhere is rithe right combo of options/glitches but didnt find it yet
this is really cool. I've been dealing with an aging Synology nas and this is something I can pick up, evaluate performance and how safe it is to serve as home for my data.
Yeah no. When it comes to backups and data storage, I would rather use a proven reliable system that’s been used and tested by millions of other users, keep these hacky stuff for your hyperland set up.
Not really, zfs is part of it, but not the whole picture, you as a user you need more than just a file system.
Truenas for example add replication, external cloud sync, gui (yes it’s important not to wipe your data with wrong command), HA, custom caching, containers to extend ot with other apps, raid-z expansion with openzfs, and other for monitoring, user management and a lot more.
Other solutions also add more than just a zfs with ssh access.
Run ZFS backed filestore on FreeBSD, have migrated it to/from Debian. At work and home, not petabyte scale but certainly multi hundred terrabyte. Over 15 years, on over 50 hosts/NAS/SAN instances, different hardware.
Run ZFS on Raspberry Pi, on home builds, on Intel, on AMD, on other ARM chipsets.
I think you're over-stating things. Debian is fine for this. I do think FreeBSD is a better platform for myself.
The code bases adhere (modulo ZFS version numbers) to a spec and you can safely migrate the pools between OS. I've done it multiple times both directions.
You can not do this with BTRFS and other Linux things, I consider this feature of (Open)ZFS a killer-context for me: It's OS portable. I wish Mac OSX hadn't walked out of the room when Oracle went legal.
There is actually a btrfs driver for Windows [0]. I've used it a few times before, and it works surprisingly well. You probably wouldn't want to use it for any serious work, but that's not because it's technically flawed, but more because it isn't extensively tested or commercially-supported.
Yet everyone is (again) lost in the details and missing the big picture, which is Linux is doing its best to rat fuck OpenZFS at every opportunity, the last of which was the elimination of write_cache_pages in 6.18 behind the GPL iron curtain a mere few months ago.
I don't know about you but I don't want to build my file storage atop hacks on top of more hacks. The kernel has made it clear non-GPL code is not welcome. Struggles will continue in perpetuity. There are better options.
I understand and I agree from an experience point of view it felt very unstable on debian and proxmox that is debian based.
I wanted to share this experience too as a warning to users investing time and money and possibly hitting instabilities that can cause raid problems and data loss. Don't know why my comment got downvoted, if I knew about this I would have handled things differently.
I usually recovered the pool thanks to other disks being fine, but beside zfs being super cool in terms of features and flexibility at the beginning it actually felt unreliable and I would not suggest it neither!
as mentioned it is probably more stable on other families but I didnt experience that yet.
would freebsd be the most reliable? or which one would have the most reliable zfs module state?
do other solutions like unraid or truenas or similar use zfs the background?
If you run ZFS with an LTS kernel you're pretty much fine. Yes new Linux releases will break existing ZFS releases - but the LTS tree is in support for long enough that this is never an issue.
I am a BSD user yet I think this is largely irrelevant in the scope of a NAS which is the conversation we have here. Even in the cases bleeding edge hardware support is relevant, the latest Linux LTS kernel has probably wider hardware support than the freebsd-current at any given point in time anyway.
FreeBSD is a great choice, but there is no need to invent silly reasons to justify using it.
> Running ZFS on anything but Solaris/Illumos/FreeBSD is asinine.
> ZFS is a permanent second-class citizen on Linux
Linux is the primary target of OpenZFS [0] [1], and has been since 2020 [2]. It may not be supported by the Linux kernel developers, but it's supported by the ZFS developers, and that's all that really matters.
> I don't want to trust my data to some half-assed out-of-tree solution that may or may not break in a week.
Sure, it's an out-of-tree module, but that doesn't mean that it will randomly break all the time; it just means that you may occasionally need to wait for a new OpenZFS release before upgrading your kernel.
> FreeBSD ZFS support has matured and is outstanding.
Agreed, but Linux and FreeBSD both use the same ZFS [3], so I don't really see how the ZFS in FreeBSD can be better than the one in Linux. The tooling and install procedure is certainly better on FreeBSD, but the actual filesystem code is the same (and is probably slightly more robust on Linux since that's going to be where most of the testing occurs).
Not a great time price-wise to be building a NAS, but I have been doing so for the last two weeks. Inside a Jonsbo N6 case, which is pretty nice with an 8x SATA backplane and drive bays (unlike the earlier Jonsbo variants).
I ended up on shucking 4x the 14 TB WD Elements Desktop. They contain helium drives, the WD140EDGZ in my case, and are about a third cheaper than 4x the 12 TB WD Red Plus drives (which are air-filled). The shucking was easier than I expected too, and the performance seems very comparable. The warranty is a definite downside (European, so no Magnuson-Moss), but I think I can even get them back in their enclosure should they fail during the 2-year warranty period.
I've put some second hand 256 GB M.2 SSDs in there as boot drives. It was a bit of a struggle to get it to work in a way that failure of one of the drives doesn't hold up booting, combined with LUKS, TPM keys and ZFS on root. Learned a lot about systemd-boot which I have never used before, but feels a lot saner to me than grub ever was. So now I have a large script which debootstraps a Debian based NAS into being.
I noticed that there are a lot of ZFS myths and cargo culting. For example TFA mentions ECC RAM, which in some circles is a must-have because ZFS would wreck your pool during a scrub otherwise, which is a myth. It's also very expensive, especially this year. You also don't need much RAM for ZFS, L2ARC doesn't use much RAM at all, to name a few others.
Still doubting about setting `dnodesize=auto` (which is the default), because there are some horror stories about that [1]. And it seems impossible to find a cloud storage provider with reasonable prices that supports `zfs send`. Rsync.net upped their minimum order to 10 TiB recently, which is far too much for my use case.
[1] https://github.com/openzfs/zfs/issues/11353
[2] https://www.rsync.net/products/zfsintro.html
I've been thinking about building my own NAS as well. Mind sharing how much did you pay for those hard drives, and what motherboard did you choose?
It was €329 per hard drive (through a reputable store), and I chose the ASRock B650M-HDV/M.2 mATX motherboard combined with a Ryzen 5 8500G. Stock CPU cooler, replaced the Jonsbo case fans with Arctic P12 Pro PST LN. I only slightly regret the PSU (MSI MAG A650GL), which could be quieter. Not that it's very noisy, and it's a great PSU otherwise, but I should've chosen one that just shuts the fan down at low power usage.
https://diskprices.com/ is great for this
You have SATA or SAS to pick from. The CPU requirements for a storage server are not high. On a typical ATX board you have motherboard SATA and can put SAS controllers in the spare PCIe slots.
My first "NAS" was two 22TB hard drives in a ZFS pool on my motherboard SATA
ATA (SATA), SCSI (SAS), and NVM (NVMe).
There should be more sites like diskprices. So refreshing to see no styling, no cookie banners, just pure information.
> Not a great time price-wise to be building a NAS
That under-states the matter. It is a terrible time, price-wise, to build a NAS.
I'd almost rather have no AI whatsoever and have storage 1/10 the price of pre-AI times.
(If there were a magical choice between having AI and significantly more expensive storage, and having no AI and some program to dump that investment money into getting and somehow leveraging significantly more available storage, that is.)
I would kill (figuratively, anyway) to have no AI whatsoever. No slop machine threatening to replace my job, or turn my job into babysitting its stupidity, and hardware would be reasonably priced? That would be awesome. AI has brought me nothing but downside.
But we now have trillionaires, aren't you happy about that? It means you might be the one some day too /s
I immigrated wanting to become a millionaire. Never found time working my ass off. Now that I get pension and tokens from Musk and Zuck, I can finally try!
AI has freed most people I know from the tedious job of writing actual emails and birthday greetings - leaving then more time to e.g. wash dishes or clean the floor.
Seriously, if arts and creativity is what sets humans apart from other animals, then AI has almost completely displaced our capacity to even consider doing these activities ourselves. People reach for AI when they should be composing a birthday greeting themselves.
Is it a genuine birthday greeting if you just let AI do the job?
Was it a genuine birthday greeting when you bought a card? Or used an online card? I don’t really see the difference. The point is you thought of them, not the actual words
With AI you don't have to think about them.
Great business opportunity there. Make a free service that sends AI generated birthday notes to people. All the user has to provide is the other persons birthday.
People cannot be relied upon to provide accurate birthdays but nobody would suffer the social faux pas of an incorrect birthday congrats note. Nor would they send it to a spam catching email, but rather are guaranteed to send it to a regularly checked address. They know the persons birthday after all.
You can then sell high quality birthday information correlated to contact information to ad agencies.
Fuck this current internet. So dystopian.
Then the receiver AI can thank the sending AI before deleting.
and i would kill (literally) every billionaire and every politician in the world to make sure everyone has full access to ai. every time it helps me with code or skipping the boring parts of college or just a random question i think about the billions of people who cant because they live in a poor country or just dont know how to use it.
ai gives people incredible power so it needs to be shared equally, not locked up and controlled. the only ones threatening to replace jobs are capitalism brained humans (or maybe they already lost their humanity way before chatgpt) who want profit at all costs and believe machines can replace people even if theres no evidence. fight the system not the tech.
I'm also planning a new home server build now and the prices are definitely relatively ass. So far I've spent 820€ on two 22 TB WD Elements HDDs, 375€ on 2x16 GB DDR5 kit, and 520€ on two 2 TB M.2 SSDs (cache). About 1700€ and I still have no server to show for it. Doesn't help that I've been procrastinating on picking the CPU and motherboard.
I’m running an 8-drive ZFS RAIDZ2 pool. I’m wondering if you know — are the free space recommendations around ZFS cargo or real?
Like I’m already giving up two full drives for redundancy (which saved my ass - I recently had two drives fail on me in quick succession — both SSDs from what looks like an identical batch) but then the advice is kinda saying I need to keep at least another drive worth of space free for the pool to perform well and not crap itself. That hurts with current prices for sure.
ZFS will auto-degrade performance if there isn't enough headroom. In addition, if you use SSD, you also want the headroom, because otherwise you end up writing and rewriting on the same small empty space which kills SSD (unless you have enterprise SSD, which have built-in headroom).
Not sure why I'm being downvoted for being factually correct (and also, why I can't edit my above comment).
ZFS will definitely degrade write performance gradually from 90% utilization, and will hit a stronger cliff at 95%+. Same with SSD, using a consumer SSD above 90%+ utilization would rapidly degrade its lifetime. The effect will be smaller for very large pools and very large files, but the effect is stil there.
I'm repeating this so that people who set up these drives know what is actually going to happen.
> Not sure why I'm being downvoted for being factually correct
Maybe because your statement about SSDs is incorrect. Consumer SSDs have spare blocks too, and wear leveling prevents the scenario you're describing.
I appreciate the reply, but my warning consumer SSD is not incorrect. While they typically have a small overprovisioning of 7%, enterprise SSDs have close to 4 times as much, exactly to allow more writes (which is very relevant if running a ZFS raid on the drive). Keeping 10-20% headroom will prolong your SSD's life significantly, and increase performance of ZFS.
> I’m running an 8-drive ZFS RAIDZ2 pool. I’m wondering if you know — are the free space recommendations around ZFS cargo or real?
I'm not entirely sure, but it seems to me that free space (and the 20% reservation) is mostly a proxy for fragmentation, and you can therefore better look at fragmentation directly. That would mean that if you mostly store large files, there shouldn't be a lot of fragmentation even at high utilization. The whole "ZFS changes allocation algorithm from 80% usage on" is something of 10+ years distant past, and lots of things around the allocator have been improved. It's also something that probably isn't too different from the performance of other filesystems at high utilization, so it shouldn't be exaggerated.
I don't think they are. I've already filled a ZFS pool almost to the brim with no adverse effects.
My experience has been escalating fragmentation past 90%, along with lower performance owing to the fragmentation.
For home usage, if you have backups raidz1 is fine (just do an incremental backup at the first sign of trouble). If you don’t have backups, then you probably shouldn’t be running a NAS in the first place.
> 4x the 14 TB WD Elements Desktop.
I recommend staying away from SATA drives (huge consumer rush) and look for SAS drives on eBay, particularly HC520 Helium drives from HGST/WD. Need a SAS3008 PCIe adapter ($20) and a SFF-8643 splitter ($30). No backplane is required. Huge lots of decommissioned drives frequently appear. I bought Qty 10* of HC520 (12TB) SAS drives for $1000 about 3 weeks ago, avg age is about 2.5 years, still well within its rated lifetime.
Yea may be some of the stuff is fear mongering and cargo culting. I was told ECC is necessary for ZFS. When the article was written, it was cheap af (2024) to buy ECC RAM so not much consideration was given to it.
-- (*) I have no idea what to do with it. Anyone has any good idea for using 120TB space? I have about 40TB unused bandwidth in the datacenter, may be host a Debian mirror? Donate storage/bandwidth to Internet Archive? Please contact me, appreciate it.
> I bought Qty 10* of HC520 (12TB) SAS drives for $1000 about 3 weeks ago, avg age is about 2.5 years, still well within its rated lifetime.
That's cheap indeed. Enough headroom for some failing disks too. How is the noise and power usage? I didn't look at SAS drives at all, because my impression was that they're very noisy. I can place my NAS in a closed off room, but it's not too far away and I was afraid SAS drives would be audible through the wall. At the same time, the shucked drive I'm using presents itself as an WD Ultrastar, which comes very close to a SAS drive, and isn't very noisy.
> How is the noise and power usage?
I think they're same as SATA drives, just different interface. AFAIK they have the same physical dimensions and same internals.
You assert that ECC RAM being necessary for ZFS is just a myth but provide no justification for why that is untrue.
Is it not the case that if you don't have ECC memory, ZFS could end up writing a checksum that does not match the data if you get a bitflip in just the right (wrong) spot?
> You assert that ECC RAM being necessary for ZFS is just a myth but provide no justification for why that is untrue.
ZFS without ECC is no more risky than any other file system / software RAID without ECC.
As no one owes you an explanation, it would take you five seconds to Google this and discover:
1. It's been disproven, with one of the original ZFS developers chiming in.
2. The original source of the rumor was a forum post that somehow became canon.
Yes, indeed. ECC RAM is better than non-ECC RAM, also for ZFS.
The myth, popularized by a notorious thread on the TrueNAS forums [1], is specifically that ZFS requires ECC RAM, and will do worse than other filesystems without it, because scrubbing will multiply a single bitflip into a failed pool.
A ZFS core developer says that that isn't the case [2]. Here's some more reasoning [3], also about many other myths.
[1] https://www.truenas.com/community/threads/ecc-vs-non-ecc-ram...
[2] https://news.ycombinator.com/item?id=18480016
[3] https://kldload.com/zfs-wiki/myths
Updated link to the post from Matt Ahrens here[1], which is one of the ZFS creators[2] not "just" a core developer.
[1]: https://arstechnica.com/civis/threads/ars-walkthrough-using-...
[2]: https://en.wikipedia.org/wiki/ZFS#2004%E2%80%932010:_Develop...
Usually if you’re using a NAS you don’t want to lose data, ZFS is not significantly more sensitive than everything else.
But everything is actually quite sensitive.
We’ve accepted lack of ECC because Intel decided it would be a product line differentiator, and serious customers who didn’t want random crashes or to lose data would buy chips with ECC.
It’s actually less of an issue these days because DDR5 has (by spec) some in-line ECC; won’t help with multi-bit errors but its an improvement on what came before.
I know that LPDDR5 has ECC, and not just single bit AFAIK, but if you enable it you lose some memory capacity (the 128 bit bus minus 16 bit for ECC error correction, making it effectively 112 bits)
The only hangup with the myth "debunking" is that the point is that the corruption doesn't happen to a per-disk buffer, but to the in-flight data before it's persisted to your stripe.
Which means all copies of the data will be corrupted. This can be anything from an irrecoverable file to complete filesystem corruption.
But generally, yeah, not any more dangerous than any other filesystem, and ECC used to be cheap so it was a no-brainer, you should have backups anyway TBH if we're being honest about storage resiliency.
What has been debunked is the "scrub of death" issue, on a scrub a bad bit flip would cause an error, which would be copied over with good data -- well it was technically good before. It would be statistically difficult to have a fault on a read, then a clean read, then a second bit flip destroying the data.
> combined with LUKS, TPM keys
Does it work? Server can reboot and use TPM to unlock rootfs? What about /boot - encrypted and tamper proof? Resists evil maid attack?
Rabbit hole, I know, but so fascinating if you solved it all :)
If you are worried about someone breaking in to your house and replacing the bootloader while leaving your drives in place I probably wouldn't use the TPM auto unlock even if in theory secure boot should be able to handle this.
But in reality that will never happen and the only actual attack you need to be worried about is junkies breaking in and flogging the drives on facebook marketplace. For which, this level of security is fine.
Some other things I find useful on NASes:
Install avahi-daemon. Samba will automatically register with it to advertise SMB/CIFS to macOS and Linux clients over DNS-SD.
Install wsdd2 so that your server will be auto-discovered by Explorer on Windows 10+ clients with SMB 1.0 disabled, too.
Your Linux hostname is probably lower-case, but by default, Samba publishes a capitalized rendering of the hostname to NetBIOS and Avahi. If this bothers you, set “host-name=something” in the [server] section of /etc/avahi/avahi-daemon.conf, and set “mdns name = mdns” in the [global] section of /etc/samba/smb.conf.
If you have macOS clients, you should enable vfs_fruit in your Samba configuration: https://www.samba.org/samba/docs/current/man-html/vfs_fruit..... There are some compatibility reasons to do this, but mostly it means you can set the “fruit:model” so that your server has a fun icon in the Finder sidebar.
To avoid the creation .DS_Store files, you can disallow them: https://ryanoberto.github.io/blog/2015/04/01/disabling-the-c.... I think you can also set “fruit:resource = xattr” to store Finder preferences in xattrs, but I haven't tried it.
Although macOS deprecated AFP in favour of SMB years ago (and are slated to remove AFP client support altogether in the upcoming macOS 27), SMB client support in macOS is still pretty miserable. The upcoming macOS 27 is set to drop AFP support, but until then I will continue to run Netatalk side-by-side with Samba. Netatalk also registers itself with Avahi, and macOS will (tellingly) use AFP preferentially to SMB, so clients will talk to the right daemon automatically.
I think it's appropriate to link to my blog post about building such a NAS but with very different technologies: dm-integrity, mdadm and XFS. The reason being that as a C/C++ dev following OpenZFS development closely, I found the focus on ginormous features over general stability and the constant problems due to the SPL/separate page cache too worrying.
Sure, I traded the convenience of kitchen sink (or Swiss army knife for the more charitable souls) ZFS for some initial pain, but I'm very happy with my choice today.
https://world-playground-deceit.net/blog/2025/06/nas-setup-l...
I still pay for snooty, and the reason for that is that when a disk goes bad (not if; when) I pop its tray out, replace the disk, pop the tray with the disk back in, click a couple of widgets, and that’s it. I know it will be rebuilt properly.
(And I know I have to do that, because when the disk fails it beeps and lights a led near the bad disk)
It’s easy to build a NAS such as the one described in this article, but in the long run, data loss is significantly more likely.
Also, any guide like this that doesn’t guide you through “disk 3 failed, this is how you safely replace it” is imho incomplete, even if it doesn’t go through telling you how you know a disk has failed.
Is snooty a autocorrect for Synology or some other product?
Indeed. Didn’t notice and it’s too late to edit now.
That is kind of exactly how zfs works though. The guide isn't complete, sure, but "rebuilding" the array is just replace the disk and run a single zfs command.
That’s comforting to know; that wasn’t true in the past for ext4 over lvm (is it true now?).
But what is that command? And how do you know which disk has gone bad?
I am sure I can get an answer from Google / Claude / ChatGPT, but a guide is incomplete without it - and the failure report should be active like a beep or flashing hardware light - I typically log into my NAS only a few times a year. A motd or other banner isn’t sufficient.
zpool-replace(8)
https://openzfs.github.io/openzfs-docs/man/master/8/zpool-re...
ZFS got this right. MDADM on ext4 somehow did not.
EDIT: ext4 on MDADM.
How ZFS gets this right: zfs(8) on zpool(8). So, basically, ext4 and mdadm can talk to each other.
> in the past for ext4 over lvm
I used to look after storage arrays for VFX places.
everytime I saw lvm I inwardly sighed. The docs were terrible, almost as bad as MDADM. snapshots were for a long time unrecoverable. You'd then have to work out what pattern of LV you had, was it a suprise raid0? or a misaligned raid1?
zfs is a night and day compared to LVM/mdadm, two tools, rich help, the man pages are reasonably good, and once you understand zfs vs zpool, you're usually good to go.
ZFS makes this completely trivial except for the "beeps and lights a led" part
To be fair, the "beeps and lights a led" part is very important in case of a dead disk in an array. The only time, I disrupted a service in production for longer than a few hours was when I didn't get the email of a degraded raid 1 array and the second disk died a few weeks later.
smartmontools makes this trivial and can email you which might be better than beeping and lights if you’re not always near your server.
I use that plus smartctl_exporter so I can do metrics and alerting off that.
That’s awesome. But a guide that does not include a howto for alerting (such as the one linked) is incomplete.
I came to the same conclusion when I built my NAS. Just Nix for the system, zfs for raid and docker compose for any service I might want to run. https://www.splitbrain.org/blog/2025-08/03-diy_nas_on_nixos
Same, using NixOS as a NAS, though it kept growing and now I'm trying to share it with other people. I use BTRFS on MDADM though. It's ended up being an all-in-one home server and router now because I was tired of the noisy power hungry rack I had in my closet.
https://HomeFree.host
I'm also using NixOS for my NAS, you should look into quadlets (docker containers managed by systemd) to manage containers with nix.
I found cockpit to be incredibly useful for managing NAS and VPS. Even though any configuration is not an issue with LLMs, having a dashboard with toggles, formatted logs and such is helpful, and I can even run shell commands on phone without ssh. In the NAS case, you can easily see the results of backup/maintenance cronjobs, manage samba (which is a huge pain in the ass to get to work properly on iPhone), and monitor disk usage
I'm sure people have reasons for taking these things as far as they do with ZFS, and everything else that goes into what is commonly considered a "NAS." But I've found great convenience in a tight NFSv3 config running from a single high capacity HDD with ext4 on a Linux machine (primary system that's always on anyway while I'm around/awake) making things available to my other devices for the electricity and overhead cost of one machine instead of multiple.
I try to keep my network configuration restrictive by default, so I'm not too concerned about possible security arguments running it from my main machine. I've probably committed some great sin here, but is plain NFSv3 and secondarily Samba (for compatibility) really not enough?
First: Do you have backups of your single high-capacity HDD? That's my biggest worry. What's your plan for when that HDD fails one day, as it will?
The main reasons people go for ZFS and a "NAS" is checksums and data integrity protection, as well as maybe not wanting to keep their primary machine awake all the time (I personally don't).
Then there are useful features like snapshots, which means I don't have to worry as much about accidentally deleting, or over-writing a file and losing data.
I don't see anything wrong with using a main machine that's up 7x24 as a NAS, don't buy things for the sake of something, but I'm worried about your reliability and bitrot protection. (Yes, it happens, I've seen it first-hand thanks to ZFS).
I have external parity for everything with rsync. I don't have any storage that isn't matched with external backups. Fortunately I've never seen any bitrot or had a drive fail on me since I tend to replace them before they do. And yeah, I could add in some extra HDDs for RAID, but this is more a personal choice because of how much I hate SATA.
Filesystems like ext4 are because I value boring and rock solid stability over semi-experimental status of modern filesystems with all the features.
It's more the single drive storage layout that is an issue in your case. No resilience to a single disk failing and you are risking all your data if your hardware starts silently corrupting data. This is assuming all your backups are done using the data on the single hard drive.
If you want to keep your setup simple I would consider the following:
- Keep a list of file hashes and check your files against this list periodically.
- Use some type of backup program that supports snapshots. Restic is a good choice.
- Get a hard drive the same size as the one you have and use SnapRAID to manage file integrity or set up a two disk mirror using btrfs.
I used this blog post as one learning resource while building my own NAS a while back: https://xyny.art/blog/2026-building-nas/
Building a NAS from scratch is really fun! A small hinderance, but definitely part of the fun as well, is the lack of a "complete resource" on the topic covering how to do every single thing you need to do. Part of the point of my blog post is actually to bring to the internet yet another opinionated NAS setup "guide" (eventhough I would hesitate to call it a guide, but if I ever had to do the same thing again I would definitely read my own post first).
I made 2 Raspberry Pi5 NAS's. one with 4x 6TB and one with 4x 12TB.
Used mergerfs and snapraid, and a simple NFS share. Absolutely perfect for Proxmox backups, our pictures, media, etc, etc. No fuss, easy replacement of drives without needing to keep drives of the same size around.
I'm good with ZFS, have been for years now managing storage for $COMPANY. And I still freaking love using zfs send/receive with proxmox ;-)
But for most at home stuff: mergerfs and snapraid are just more logical.
I really, do not want to have a big server rack lying around at my house. I have a couple of SSDs that are not being used and 3 USB HDD drives. I also have a PN50 that I am not using as well.
I am thinking of buying a USB bay with 5 SSD slots in it and then 3 HDD drive. My use case is very, very cold. It is mostly just readonly data with some rclone sync every week.
Does anyone have a suggestion? I am pretty much relying on ZFS to do all the redundancy for me.
USB/SATA adapters are incredibly flaky. Some don't support TRIM, some have major firmware bugs, many overheat during long data transfers and disconnect from the host. I'd strongly advise against using them for any important data.
10 months ago I've built a Raspberry Pi 5 mini NAS with 3 SSDs connected through RADXA Penta Hat. It runs OpenMediaVault, system is on the SDcard, other data are on the SSD ZFS pool. I have autosnapshots enabled, and I tune compression methods on specific datasets (lz4 for almost everything, zstd for file backups).
We use it for storing (backups, media files), playing (PaperMC), and watching (Jellyfin). I can only complain about the lack of hardware decoding in Raspberry Pi 5. Jellyfin loads CPU much if I enable transcoding so it's always disabled. If I knew this, I'd consider a cheaper and faster, but less popular, RADXA machine. Storage is fast enough for me, rsync and Samba speeds are usually limited by my network. PaperMC also runs without a hitch, thanks for asking!
As I didn't have high requirements for the machine, I also considered USB Bays at first but they wouldn't go well with ZFS.
I'd probably just buy a cheap prebuilt PC with a big case, or surplus enterprise tower. You can get cheap LSI PCI cards and do miniSAS to SATA if needed.
The biggest concern I'd have with USB is power delivery to the hard drives, but I haven't even done the napkin math so maybe it's fine. The SSDs seem like they might be a waste of money. USB hard drives have a poor reputation, but I don't have a ton of experience to say how much of that is deserved. On a practical level, I'd also be concerned about knocking the cable out.
This post mentions https://github.com/wyager/zfs-backup for (offsite) backups. Why would they recommend this over something more established like https://github.com/jimsalterjrs/sanoid? Has anybody tried it?
It's pretty minimal and straightforward written in Haskell. Probably can write one from scratch with Claude now.
What's next!? Let Claude analyse clinic visits!? Oh well...
Just yesterday I was brainstorming with ChatGPT about this. I have an ancient QNAP plus a slightly less ancient NUC running PiHole, Wireguard and other services. Both need replaced, so why not combine them?
I don't know much about ZFS, but it sounds like I need to learn. Docker may have conquered the world, but I plan to stay with LXD for services.
The one thing I take issue with: an appliance like this runs 24/7. It should be low power and fanless. A processor like the N100 seems like the obvious choice.
It also surprised me that the author said "4 Cores, Xeon Server CPU can be had for cheap".
But the specs also said ECC RAM and I don't think the N100 supports that.
> But the specs also said ECC RAM and I don't think the N100 supports that.
If I remember correctly it can in theory but in practice I have never seen a N100 with ECC.
Tangential, but about this:
> I am creating a RAIDZ1 (RAID 5) zpool. That means 1 drive redundancy in-case of failure
A friend once told me that RAID5 has a high latency cost, because every Write requires a Read to update the stripes across all drives, and while this made sense when drives were expensive, nowadays you might as well do a RAID10 instead, and trade space for latency.
Is this still true with ZFS RAIDZ1?
> and while this made sense when drives were expensive
I don't have the answer to the latency question, but HDDs have shot up in $/TB over the last couple years too. They are once again kind of expensive.
The RAID5 write hole is not present in RAIDZ1 I believe.
RAIDZ1 will add more stress to the consumer ssd's as to enterprise one due to surprinsingly different hardware. Consumer ssd's life times are calculated on a 8 hour shift (the tbw) and enterprise are calculated on 24/7.
Please - dont - use - consumer ssd's - with zfs raidz1
It's complicated, but https://jro.io/capacity/ actually walks you though how it works, towards the middle of the page.
``` Unlike traditional RAID5 and RAID6 implementations, ZFS supports partial-stripe writes. This has a number of important advantages but also presents some implications for space calculation that we'll need to consider. Supporting partial stripe writes means that in our 7wZ2 vdev example, we can support a write of 12 total sectors even though 12 is not an even multiple of our stripe width (7). 12 is evenly divisible by +1 (3 in this case), so we don't even need any padding. We would have a single full stripe of 7 sectors (2 parity sectors plus 5 data sectors) followed by a partial stripe with 2 parity sectors and 3 data sectors. This will be important because even though we can support partial stripe writes, every stripe (including those partial stripes) need a full set of p parity sectors. ```
I've been thinking about setting up something like this for a while. I have a Broadwell dual socket Xeon workstation that I'm going to upgrade to Proxmox. Would it be reasonable to run something like this as an LXC or VM or would you put it in the base kernel?
To be totally honest, I don't think I can live without ZFS anymore. Deduplication and snaphots in 2026 are a must.
and checksums!
Rather than 'plain' debian you can put it on Proxmox, and enjoy the bliss of Proxmox Backup Server.
One alternative for those who don't want any of the major NAS vendors, just use RHEL10. It's free up to 16 licenses, it's ultra stable, cockpit is a very mature gui for a lot of maintenance tasks.
It's a set and forget OS that will run for years without requiring your attention. But these days it has decent container support for hosting services on.
Or rocky, which is a 1:1 clone of RHEL that doesn't require licenses. https://rockylinux.org/
The problem with RHEL is that the free version exists at the sufferance of IBM, a company not well known for being motivated by keeping tech enthusiasts happy. I would use Debian, personally. Not as long of a support cycle as RHEL, but still quite stable and no possibility of corporate rug-pulls.
Also you can use zfs on a proxmox host and use that both for NAS duty and for the VMs.
For some reason people insist on doing truenas on top of proxmox and then introducing a networking layer between everything they do. Noooo…
its probably dumb but what i do is use proxmox with a debian VM with docker installed and each docker container gets a virtual disk i make on the proxmox host. obviously more involved than running unraid or truenas but i think the complexity underneath is simpler.
Thats perfectly reasonable. Double isolation but that isn’t too costly.
I’m talking more about people doing the same as you except they’re linking the VM storage to another vm (truenas) over network despite it all being on same host. Think it’s mostly because people don’t want to deal with zfs via command line
To this day I still use a ZFS array for my critical backup storage. I've migrated over to using snap raid + mergerfs for my larger Linux iso storage array. Simple enough and I can pull a drive on it's own without any other stuff.
Can anyone recommend a good server for a homelab to use for a storage purpose like this?
It's a horrible idea likely, but I have an ancient old Dell PowerEdge R510. Probably sucks way too much energy, but it does what it does and the price of SSDs have skyrocketed so I'm not touching it.
I'm sure there's better options now but the HP ProLiant MicroServers (used).
They support ECC ram, 4 caddies, one extra PCIe slot, and to my knowledge you're not cpu limited for a zfs file server usecase.
Keep in mind though, all you need is linux* support, iDRAC, ECC if you're a snob, and drive bays ... and that's basically any free server.
In my extremely opinionated opinion I would only get used enterprise server gear, because a zfs file server will just work unless hardware fails. And a UPS.
*ZFS will be a more natural choice on FreeBSD. It's better documented, and will meet Linux 1:1 in hardware compatibility for this.
I'm still running an old Gen 8 MicroServer. Modern drives can actually saturate the SATA controller, and because it only has a single PCIe slot I can't add both a 10Gb NIC and a storage controller - I went with the 10Gb NIC.
It works well enough though and has lasted me over a decade at this point. 16GB DDR3 ECC, an old 4 core/8 thread Xeon, 4x14TB drives and the Mellanox NIC.
I got a gen10 plus microserver and liked it so much that I got a second one.
Throw FreeBSD on it and add a couple lines to /etc/exports and rc.conf and it's a NAS right out of the box
Agreed. I have used a HP N40L ProLiant MicroServer since 2013 as home NAS and Time Machine backups via samba. Rock solid hardware, incredibly expandable, and today runs FreeBSD 15.1 with ZFS. Additional hardware modifications include; CD-ROM replaced by two 3.5" HDDs on mounts (now six HDDs of 10TB each in ZRAID1), a SAS card to add two mirrored bootable SSDs underneath CD-ROM drive space, a 2x 2.5G NIC (limited to 4GB/s slot) for dedicated NFS link, while additional internal SATA and external SATA ports unused. Next: replace PSU fan with quieter Noctua fan.
Not strictly a recommendation, but Terramaster is a good brand to look at if you want Synology-shaped hardware which can run TrueNAS or Proxmox or any flavour of Linux you want.
Along with various other devices (including a large Synology which I wouldn’t buy today), I run Proxmox on a small two bay+two nvme Terramaster. I have a bare bones Ubuntu LXC running Samba configured for Apple Time Machine, an VM running Scrypyed, and PBS for Proxmox backups. Nothing on it is critical so I don’t bother with any storage redundancy.
I have the F8 Plus, great little unit. It did need a BIOS update when I first got it to enable Proxmox/other OSes to work properly.
Recently replaced the internal USB boot drive with a small NVMe USB enclosure; using a 90-degree USB connector and using a dremel to sand away an opening for the cable to come out so I could mount the enclosure externally.
A friendly reminder since it's probably relevant: when's the last time you tested disaster recovery for your own setup? If you haven't verified recovering it, you don't have an offsite backup.
I had a cloud backup (Backblaze B2, using rclone and encryption) for my home NAS. Some unlucky drive failures later, I was getting ready to recover from my Backblaze backup... and then I couldn't find/remember where I saved the rclone encryption backup.
I lost all data in that NAS, including irreplaceable personal/family photos, due to that mistake. My lesson to share: please verify you can indeed recover from backups.
I killed 2x 4tb Nvme drives on Pciexpress with ZFS raid1 under proxmox, got them replaced, tried again on both pci-express and usb adapter kept getting io problems there too with zfs, drive gets disconnected during scrub or high load, tried already kernel or power management options for pciexpress and usb without sucess, managed to reproduce with high load.
or proxmox ( especially community edition) is fucked or zfs is still unstable, surprisingly with different drives on different interfaces I obtained same results, didnt swap proxmox for clean os, that might being some changes since modules and options would be different i guess. ( drives firmware etc are fine and performing well when inspected with proprietary windows tools)
just search zfs nvme pcie or usb problema or disconnect and you see similar stability problem for different users in different cases (os, drives etc), but also unraid and others, maybe somewhere is rithe right combo of options/glitches but didnt find it yet
> usb adapter kept getting io problems there too with zfs, drive gets disconnected during scrub or high load
That's usually caused by the adapter chipset overheating. Don't use USB adapters for important data.
this is really cool. I've been dealing with an aging Synology nas and this is something I can pick up, evaluate performance and how safe it is to serve as home for my data.
Very cool
Yeah no. When it comes to backups and data storage, I would rather use a proven reliable system that’s been used and tested by millions of other users, keep these hacky stuff for your hyperland set up.
I've lost more data to "proven reliable systems" than to my homegrown hacked-up stuff (which may be because I trust the latter much less).
This. My synology nas got pwned so many times i cant remember.
> I would rather use a proven reliable system that’s been used and tested by millions of other users
You're describing ZFS.
Not really, zfs is part of it, but not the whole picture, you as a user you need more than just a file system.
Truenas for example add replication, external cloud sync, gui (yes it’s important not to wipe your data with wrong command), HA, custom caching, containers to extend ot with other apps, raid-z expansion with openzfs, and other for monitoring, user management and a lot more.
Other solutions also add more than just a zfs with ssh access.
Stopped reading at "Debian".
Running ZFS on anything but Solaris/Illumos/FreeBSD is asinine.
ZFS is a permanent second-class citizen on Linux (due to usual open-source politics). This will never resolve.
I don't want to trust my data to some half-assed out-of-tree solution that may or may not break in a week.
FreeBSD ZFS support has matured and is outstanding. Quality-wise it has reached parity with Illumos.
If you can afford Solaris then you're probably not building your own NAS from parts of lesser computers.
Run ZFS backed filestore on FreeBSD, have migrated it to/from Debian. At work and home, not petabyte scale but certainly multi hundred terrabyte. Over 15 years, on over 50 hosts/NAS/SAN instances, different hardware.
Run ZFS on Raspberry Pi, on home builds, on Intel, on AMD, on other ARM chipsets.
I think you're over-stating things. Debian is fine for this. I do think FreeBSD is a better platform for myself.
The code bases adhere (modulo ZFS version numbers) to a spec and you can safely migrate the pools between OS. I've done it multiple times both directions.
You can not do this with BTRFS and other Linux things, I consider this feature of (Open)ZFS a killer-context for me: It's OS portable. I wish Mac OSX hadn't walked out of the room when Oracle went legal.
I guess you can try Windows next - https://github.com/openzfsonwindows/openzfs
> You can not do this with BTRFS
There is actually a btrfs driver for Windows [0]. I've used it a few times before, and it works surprisingly well. You probably wouldn't want to use it for any serious work, but that's not because it's technically flawed, but more because it isn't extensively tested or commercially-supported.
[0]: https://github.com/maharmstone/btrfs
There is Fuse support in BSD. I don't consider that a good choice for this role.
Sure you can migrate pools.
Yet everyone is (again) lost in the details and missing the big picture, which is Linux is doing its best to rat fuck OpenZFS at every opportunity, the last of which was the elimination of write_cache_pages in 6.18 behind the GPL iron curtain a mere few months ago.
I don't know about you but I don't want to build my file storage atop hacks on top of more hacks. The kernel has made it clear non-GPL code is not welcome. Struggles will continue in perpetuity. There are better options.
I understand and I agree from an experience point of view it felt very unstable on debian and proxmox that is debian based.
I wanted to share this experience too as a warning to users investing time and money and possibly hitting instabilities that can cause raid problems and data loss. Don't know why my comment got downvoted, if I knew about this I would have handled things differently.
I usually recovered the pool thanks to other disks being fine, but beside zfs being super cool in terms of features and flexibility at the beginning it actually felt unreliable and I would not suggest it neither!
as mentioned it is probably more stable on other families but I didnt experience that yet.
would freebsd be the most reliable? or which one would have the most reliable zfs module state?
do other solutions like unraid or truenas or similar use zfs the background?
And yet TrueNAS is moving away from BSD towards … Debian!
You can use past tense there.
AFAIK this is because TrueNAS is trying to be all things to everyone, and they like Docker more than BSD jails.
If you run ZFS with an LTS kernel you're pretty much fine. Yes new Linux releases will break existing ZFS releases - but the LTS tree is in support for long enough that this is never an issue.
Unless you need driver support only found in newer kernels. Then you are screwed.
Do I want my hardware to work or do I want to be able to read my files?
I am a BSD user yet I think this is largely irrelevant in the scope of a NAS which is the conversation we have here. Even in the cases bleeding edge hardware support is relevant, the latest Linux LTS kernel has probably wider hardware support than the freebsd-current at any given point in time anyway.
FreeBSD is a great choice, but there is no need to invent silly reasons to justify using it.
> Running ZFS on anything but Solaris/Illumos/FreeBSD is asinine.
> ZFS is a permanent second-class citizen on Linux
Linux is the primary target of OpenZFS [0] [1], and has been since 2020 [2]. It may not be supported by the Linux kernel developers, but it's supported by the ZFS developers, and that's all that really matters.
> I don't want to trust my data to some half-assed out-of-tree solution that may or may not break in a week.
Sure, it's an out-of-tree module, but that doesn't mean that it will randomly break all the time; it just means that you may occasionally need to wait for a new OpenZFS release before upgrading your kernel.
> FreeBSD ZFS support has matured and is outstanding.
Agreed, but Linux and FreeBSD both use the same ZFS [3], so I don't really see how the ZFS in FreeBSD can be better than the one in Linux. The tooling and install procedure is certainly better on FreeBSD, but the actual filesystem code is the same (and is probably slightly more robust on Linux since that's going to be where most of the testing occurs).
[0]: https://github.com/openzfs/zfs#supported-kernels-and-distrib...
[1]: https://github.com/openzfs/zfs/pull/8987
[2]: https://github.com/openzfs/zfs/releases/tag/zfs-2.0.0
[3]: https://docs.freebsd.org/en/books/handbook/zfs/
I run ZFS on Linux and FreeBSD and FreeBSD is less of a faff. If you don’t need docker on your NAS, I would go FreeBSD as well.