Pool status: Unhealthy

[dave_scream]

Yesterday I first time installed this system for my 2 new 4tb drives. Still copy data to my new NAS storage.
Using Truenas CORE 12U1.

Today I have alert:
Pool zraid1 state is ONLINE: One or more devices has experienced an unrecoverable error. An attempt was made to correct the error. Applications are unaffected.
2020-12-20 15:21:50 (Europe/Moscow)

and Pool status on dashboard is unhealthy.

What I should do next? where and what to check

 

[joeschmuck]

In my signature below is a link to Hard Drive Troubleshooting Guide. Read that and it will have you check your hard drives out. Did you perform a proper burn-in testing of your system to ensure it's a reliable performer?

Also, please follow the forum rules, when asking a question like this we ask that you provide the system specs (make/model), how much RAM, and other information. We need this information in order to provide you the best advice possible and to quickly solve your problem. It helps us helps us help you. For example if you are running 4GB RAM, that could be the cause of your issue. My first thought is to verify your hard drives are not having any problems. Even new hardware can die a premature death.

Good Luck.

 

[dave_scream]

For example if you are running 4GB RAM, that could be the cause of your issue

Im running 3gb RAM. with mirrored pool 4gb+4gb WDC WD40EZRZ-22GXCB0 (no SMR). One disk have checksum errors:

Show

Why 8gb ram needed for simple hard disk operations + web interface?
Thanks for pointing to hard drive troubleshooting guide.

 

[joeschmuck]

Why 8gb ram needed for simple hard disk operations + web interface?

The operating system needs this much RAM in order to work effectively. With low RAM situations the system will SWAP out RAM to the hard drive so it can run an application/function, then when the RAM is free or just needed again the stuff pushed to the hard drive will be reloaded, and that could mean something else it removed from RAM and placed on the hard drive. So you need to have enough RAM to make it work well. Constantly using the SWAP space means your hard drives take a beating and everything slows down. If you enabled any extra features like Plex or other VM/Jail programs, your situation would be unsustainable with 3GB RAM.

You can also check your SWAP space to see what has been used. It should be a Zero value. On the GUI (I'm using FreeNAS 11.3U5) and it should be similar layout, select the Dashboard -> Pool -> Disk Reports -> On the drop down select MEMORY and scroll down to SWAP Utilization. At the bottom of the chart it should say "Used" and Min/Mean/Max. All three values should be "0". Having a few very small values is not terrible, any value other than zero indicates you are short on RAM.

If you are looking for a NAS program that will run on less RAM then you could use an older version of FreeNAS or check out NAS4Free but I think they desire 4GB RAM minimum, I could be wrong.

But check the SWAP Utilization value and also check your hard drives out. I'd run a SMART Long test on them and then check the results. If all is good then they are unlikely to be your issue.

 

[pschatz100]

If you are looking for a NAS program that will run on less RAM then you could use an older version of FreeNAS or check out NAS4Free but I think they desire 4GB RAM minimum, I could be wrong.

NAS4Free is now called XigmaNAS. Yes, they don't require as much RAM as does FreeNAS to actually run - but they document that performance is better when more RAM than the minimum is used. I have not used XigmaNAS personally, so I cannot comment on the trade-offs or the performance when minimal RAM is installed..

Personally, I would not bother with old versions of FreeNAS. You would have to go back pretty far to find a version that will run well with less than 4GB RAM. If it is not possible to add RAM to FreeNAS' recommended minimum, then I would look elsewhere - either XigmaNAS or one of the Linux-based NAS systems. Just keep in mind that, whatever system you go with, performance will be limited by low RAM.

 

[joeschmuck]

Personally, I would not bother with old versions of FreeNAS. You would have to go back pretty far to find a version that will run well with less than 4GB RAM.

You know, I thought FreeNAS 9.3 was still in the download section, it is not. It runs well on 4GB RAM and while running MiniDLNA in a jail. I think it would run on 3GB RAM but when I was testing it on a VM, I think I ran it down to 2GB RAM without issue. That was a long time ago.

NAS4Free is now called XigmaNAS.

Interesting, I'll have to look into it again, see what it offers and doesn't. Maybe I'll spin up a VM of it to see what it looks like. Thanks for the feedback!

 

[Redcoat]

I thought FreeNAS 9.3 was still in the download section, it is not

Hi, Joe - try https://archive.freenas.org/9.3/RELEASE/x64/

 

[danb35]

You know, I thought FreeNAS 9.3 was still in the download section, it is not. It runs well on 4GB RAM and while running MiniDLNA in a jail. I think it would run on 3GB RAM

I'm pretty sure @jgreco was insisting on 8 GB minimum back to the days of 8.x. Even today, it will run with less than 8 GB--until it doesn't any more. And there doesn't seem to be much warning of when that's going to be.

 

[Jailer]

I'm pretty sure @jgreco was insisting on 8 GB minimum back to the days of 8.x. Even today, it will run with less than 8 GB--until it doesn't any more. And there doesn't seem to be much warning of when that's going to be.

I started on 9.2.1.7 and both he and @cyberjock were when back then.

 

[pschatz100]

I recall moving from 4GB when I was on version 7.x to 8GB when I upgraded to 8.3 I was interested in jails and added the memory when I decided to learn about using jails. Back then, I was running the system as a NAS and basic DLNA server - a very limited scope.

I also seem to recall that memory became more of an issue when the system migrated to ZFS and dropped support for UFS.

 

[joeschmuck]

I'm pretty sure @jgreco was insisting on 8 GB minimum back to the days of 8.x. Even today, it will run with less than 8 GB--until it doesn't any more. And there doesn't seem to be much warning of when that's going to be.

lol, I started my involvement when FreeNAS 8.0 came out in May 2011, I was involved in programming and alpha/beta testing and building code and compiling it as a supporting user, a lot of us did this and it took my computer over 6 hours to recompile the code, yes I had a slow machine but it wasn't about being fast, it was about getting the code correct and testing it before others used it. 4GB RAM was sufficient (hence the 32 bit version aka x86), and the last offered 32 bit version was 9.2.1.9 in Nov 2014 (versioning was a little different back then). While 6GB was the lower limit for certain ZFS features to be active, that meant you had to run the 64 bit version to get those features, but you lost only a small amount of performance as a home system. The 8GB RAM recommendation was a little more forceful for FreeNAS 9.3 when we stopped building 32 bit versions but a basic NAS service would run just fine on version 9.3 using 4GB RAM for a basic home system. If you were building a monster system, of course you would need more RAM. At 11.x I requested the installation program display a warning about RAM below 8GB (I think specifically 7.5GB) because with 11.x we were seeing problems with systems becasue users were running with 4GB RAM. The system wasn't stable in all situations. Well that is the history lesson for today.

Cheers!

 

[jgreco]

I'm pretty sure @jgreco was insisting on 8 GB minimum back to the days of 8.x. Even today, it will run with less than 8 GB--until it doesn't any more. And there doesn't seem to be much warning of when that's going to be.

I made the original edit to the manual that made 8GB a requirement for ZFS. Dru questioned me a bit about it and I gave a bunch of examples of threads where this appeared to be a major factor, said I didn't know the root cause but that anecdotally we weren't seeing this on reasonable 8GB systems, and it stuck. There are a bunch of examples of corrupt pools especially on small AMD APU 4GB systems "back in the day" rendering pools ruined. I feel it is likely that the underlying issue has been fixed, but in the meantime, the middleware has grown to a size where this is still a good idea.

Remember, kids, just because it might seem to boot OK on 1GB of RAM doesn't mean it's a good idea to run it that way.