Virtualization Available Memory: 0.00 bytes

[ravingamm]

Hello,

I've recently changed over from TrueNAS Core 12.x to TrueNAS Scale 21.08 BETA.1.
At the moment I'm loving the new build.

The TrueNAS build is a physical install with a total of 64GB RAM installed in the machine, this is confirmed with the dashboard and console memory reports.

I have been noticing an potential issue with the memory utilisation discrepancy between the front dashboard Memory display/reporting memory graph and the virtualization memory display.

On the dashboard the Free Memory is showing 15GB~ free and the reporting Memory Physical Memory utilization is also showing 15GB~ free.
However, when I go over to the virtualization menu the page displays "Available Memory: 0.00 bytes - Caution: Allocating too much memory can slow the system or prevent VMs from running". It will allow me to create new machines, but it does display an message warning about the low memory.


I have also ran the free memory command on the console which confirms the dashboard and reporting figure.

Code:

nas# free -g  -t
               total        used        free      shared  buff/cache   available
Mem:              62          45          14           0           2          15
Swap:             23           0          23
Total:            86          45          38

I'm running a total of six virtual machines.
1 - 8GB RAM - Microsoft Server 2019
2 - 4GB RAM - Microsoft Server 2019
3 - 2GB RAM - Ubuntu 18.04
4 - 1GB RAM - Ubuntu 18.04
5 - 8GB RAM - Microsoft Server 2019
6 - 4GB RAM - Ubuntu 18.04

Totalling 27GB assigned to the virtual machines.
All the virtual machines have the guest software installed, either via apt-get or the microsoft virtio 1.90 software package.

Is this as expected from the system or should the Virtualization page show the same as the Memory being reported by the system?

thanks
Gavin.

 

[李仁博]

I have same promble. find solution?

 

[NoxiousPluK]

I have the same 'issue' here. Did either of you ever find any solution?

 

[sretalla]

Did either of you ever find any solution?

I don't see a lot of reports of this exact issue on the released versions (this issue was reported during the Beta). I would suggest that installing a released version would be some step toward a solution.

 

[李仁博]

I don't see a lot of reports of this exact issue on the released versions (this issue was reported during the Beta). I would suggest that installing a released version would be some step toward a solution.

Version: TrueNAS-SCALE-22.02.2
Problem still there.

The vm was created when the version is beta。

 

[sretalla]

The vm was created when the version is beta。

I wouldn't see any reason not to try re-creating the VM (you can just re-attach the same zvol/disk).

 

[cwagz]

Mine shows zero available. All my vms were created in 22.02.2.

After a reboot it will show some memory available but it declines to zero after several hours / days. My system has 64GB ram.

 

[sretalla]

OK. It sounds like somebody should be filing a bug report in Jira. I think this seems to be a real bug of some kind.

 

[NoxiousPluK]

After more searching it appears the memory is reserved for ZFS's cache. There used to be a way to set that easily in TrueNAS Core, but no longer in TrueNAS Scale apparently. I decided to just ignore it and move on with my day

 

[RafaelSoaresP]

I'm having the exact same issue on my 22.02.1 server (installed as is, not updated from beta). Dashboard shows 5.8Gb free memory, but the virtualization page show 1.19Gb available.

 

[inman.turbo]

instead of scaling back ARC when a vm started which needs some of that memory, scale will just warn you, then crash your system (out of memory)

 

[Ericloewe]

@inman.turbo, I must kindly ask that the discussion not be spread out all over the place.

Scale memory utilization

There was an additional fix related to memory usage here: https://github.com/truenas/middleware/pull/9125 TL;DR you can maybe take a nightly for a spin and see if usage is stabilized. Otherwise wait for 22.02.2. Above fix (unlike charts one) shouldn't be hard to hot-patch. Will this fix...

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