So, for the last few months, I have had a "memory" problem in my TrueNAS.
For years everything was stable and working great, but about a month+ ago I started having some strange problems.
1. All of a sudden I have corrupted files in the pool, it is discovered in the monthly scrub that it does. It's happened twice now (hopefully it won't happen again) once it was files I haven't touched in years so at first, I thought maybe that was somehow the problem. But then it also happened with really new files. I follow it but don't understand how it suddenly happens. The drives themselves are perfectly fine. And right now I've taken care of the corrupted files and everything currently looks normal.
- I also had errors in the boot pool but it worked out, probably there was an improper connection because I disconnected and connected, restarted the system, scrub, and everything worked out (for two months everything has been quiet in this part). I thought I'd mention that too.
2. My main problem, things just crashing for me,
This will be a bit long because I'm going to go into detail about everything so sorry in advance.
I noticed in the last few weeks that my Plex and qbit crashing (each has its own jail) at the same time. (I attach a screenshot)
Now if you look at the screenshot you will see that the error is that he has run out of swap but he has a lot of swap space, I checked and swap has never (in the last year) exceeded the 1GB out of the 2 he has, so this cannot be the problem.
The most obvious thing that is wrong is the use of Memory in the Dashboard
The "Services" takes all the RAM (1GB remains for ZFS and zero free space)
And I found what the problem is,
In the Plex jail it is connected to another file server (DSM) in NFS and the second I do umount to the NFS share in the jail the usage of the "Services" drops significantly (from 10GB to 4-3GB)
So he's making all the problems, at least that's what I think. If it's not the NFS I have no idea what's going on here. Because if I think back since I connected the NFS all my problems started...
Now it's probably some kind of NFS cache, the problem is that I haven't found a way to cancel it. From what I read the cache is off by default, so...
I also opened another post about this, but no one responded ):
www.truenas.com
Another thing that happens at the same time that the jails crash is that my Proxmox performs a backup for one of my VMs, and it seems that in the middle of an SMB transfer to TrueNAS, everything crashes, and the backup fails, but if I restart all my jails and start the backup again, everything works perfectly fine. Plus I have another backup of VMs on other days of the week and they don't cause problems... I don't know if it's related but wouldn't hurt to mention it.
In any case, after reading all this, I would appreciate your help in understanding what is going on here.
Like I said I think it's NFS cache but I have no idea how to disable it...
The command I used to mount the NFS into the jail:
Specifications:
CPU: i3 540 (I hear them laughing at me, planning to upgrade when I can)
RAM: 16GB (I increased it from 8GB two months ago)
HDD: 3X WD Red 3TB
OS Drive: 120GB SSD
TrueNAS 12.0-U8.1
Waiting for your help. And thanks for your help in advance.
For years everything was stable and working great, but about a month+ ago I started having some strange problems.
1. All of a sudden I have corrupted files in the pool, it is discovered in the monthly scrub that it does. It's happened twice now (hopefully it won't happen again) once it was files I haven't touched in years so at first, I thought maybe that was somehow the problem. But then it also happened with really new files. I follow it but don't understand how it suddenly happens. The drives themselves are perfectly fine. And right now I've taken care of the corrupted files and everything currently looks normal.
- I also had errors in the boot pool but it worked out, probably there was an improper connection because I disconnected and connected, restarted the system, scrub, and everything worked out (for two months everything has been quiet in this part). I thought I'd mention that too.
2. My main problem, things just crashing for me,
This will be a bit long because I'm going to go into detail about everything so sorry in advance.
I noticed in the last few weeks that my Plex and qbit crashing (each has its own jail) at the same time. (I attach a screenshot)
Now if you look at the screenshot you will see that the error is that he has run out of swap but he has a lot of swap space, I checked and swap has never (in the last year) exceeded the 1GB out of the 2 he has, so this cannot be the problem.
The most obvious thing that is wrong is the use of Memory in the Dashboard
The "Services" takes all the RAM (1GB remains for ZFS and zero free space)
And I found what the problem is,
In the Plex jail it is connected to another file server (DSM) in NFS and the second I do umount to the NFS share in the jail the usage of the "Services" drops significantly (from 10GB to 4-3GB)
So he's making all the problems, at least that's what I think. If it's not the NFS I have no idea what's going on here. Because if I think back since I connected the NFS all my problems started...
Now it's probably some kind of NFS cache, the problem is that I haven't found a way to cancel it. From what I read the cache is off by default, so...
I also opened another post about this, but no one responded ):
NFS client in a Plex jail RAM issues
Hi everyone, I have a problem that I noticed in the last few days. For the past 3 months, I've been running an NFS connection (from another storage server) into a jail running Plex and it works great. The problem I noticed is that the RAM in TrueNAS fills up after a few hours to a level where...

Another thing that happens at the same time that the jails crash is that my Proxmox performs a backup for one of my VMs, and it seems that in the middle of an SMB transfer to TrueNAS, everything crashes, and the backup fails, but if I restart all my jails and start the backup again, everything works perfectly fine. Plus I have another backup of VMs on other days of the week and they don't cause problems... I don't know if it's related but wouldn't hurt to mention it.
In any case, after reading all this, I would appreciate your help in understanding what is going on here.
Like I said I think it's NFS cache but I have no idea how to disable it...
The command I used to mount the NFS into the jail:
iocage fstab -a Plex IPofanotherstorageserver:/volume1/linux-isos /mnt/linux-isos2 nfs rw 0 0
Specifications:
CPU: i3 540 (I hear them laughing at me, planning to upgrade when I can)
RAM: 16GB (I increased it from 8GB two months ago)
HDD: 3X WD Red 3TB
OS Drive: 120GB SSD
TrueNAS 12.0-U8.1
Waiting for your help. And thanks for your help in advance.
Last edited: