My homelab "NAS" is unfortunately just a few USB based external disk enclosures, externally powered. Is there no way of making these reliable ? Every so often (maybe once a month) I get timeout errors or some kind of issues with at least one of the disks.
How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
151–160 of 265 posts
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#152Earlier quoted context omitted.
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]…
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)…
DDR5 on-die ECC is to achieve acceptable yields in the face of denser process nodes that decrease the reliability of RAM cells. It’s not clear how much of an improvement that is to what we had before, other than allowing for higher RAM speeds. It doesn’t replace side-band ECC.
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#153Not 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-fil…
> 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 signifi…
I'm doing it anyway and I've found some secondhand deals. Maybe COVID homelabbers are offloading gear?
I built a 24 TB HDD NAS in a 36 bay chassis for around $1000 all-in: mb, ram, rails, chassis, rack, disks, hba, nic
Awful Watts/TB but the plan is to run it and the GPU rig on solar.
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#154Earlier quoted context omitted.
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…
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…
rsync does not protect you from bitrot unless you have some script that specifically collects the rsync log and tracks when existing files change, and you somehow know every file that should not have changed and get alerted that a file changed when it shouldn't have.
Even with that, that is still just 2 equally authoritative copies, without any way to know which one suffered the bitrot.
Ok the tie-breaker data could come from history. Yesterdays log and the day before gives you the extra data points to say which side changed. As long as the log itself is somehow above reproach.
Except this script is a myth anyway. You would still need to have something where you tag files as "this file shall never change again, so if it ever appears to, tell me so I can ok or reject the change." and you would have to actually do that tagging and reviewing.
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#155I 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
This is what I'm hoping to do. I haven't done much research yet, so I look forward to reading about your learnings. (Also to the person who responded to you with their experience and link.)
Thanks for saving me probably some hours...
EDIT: I'm also coming from an old Synology NAS from the ~2015 era.
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#156I 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…
[deleted]
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#157Earlier quoted context omitted.
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…
How do you know you haven't seen bitrot? What rsync arguments do you use to error out when an old, untouched file suddenly changes?
I suppose I couldn't guarantee I haven't, but I keep a total backup, and other backups based on file lists. I keep a record of every file of importance that I've ever written/modified/interacted with, and those lists themselves are also git managed.
I compulsively look at the rsync backup running to see what's going to transfer, and typically do a dry-run first. That's no perfect solution, but it works for me. If I see something odd I don't quite remember, I check the hashes between both drives, and every time it turns out it was just a path change since I try to keep my data as organized as possible.
rsync arguments are just the plain `--archive --acls --xattrs --verbose` and depending on which backup I'm doing, `--recursive`, `--delete`, `--files-from=`. Nothing other than vanilla at all.
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#158Earlier quoted context omitted.
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…
What do you dislike about SATA?
The cables and how they have to be managed/positioned in a case. I've had panics over a drive failing when it was just the cable after I'd already replaced the drive, restored data, and ran tests on the old drive that turned out to be fine each time.
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#159Earlier quoted context omitted.
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…
What do you use for external parity? Par2? If you were to replace your current drive with a new larger one and your RAM or your SATA controller silently corrupted the files how would things play out? Would these corrupted files propegate to the backups? Ext4 is battle tested so I understand your reasoning. I think you just need to figure out a way to detect silent corruption and a way to snapshot your files in case t…
Misspoke. I didn't mean that type of parity, but just hashes, and a matching drive (in make and capacity) externally for an exact copy.
Re: How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)
#160Earlier quoted context omitted.
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…
What an incredibly rude comment