[Solved] VM Keeps Pausing

[N4TH4N]

[Solved]: Issue was that my BTRFS format cache drive was fully allocated even though it was reporting it had 47GB free space.

 

Solution was to run a balance on the cache drive and then update to version 6.4 or newer. I was on 6.3.5 which had problems with BTRFS drives.

btrfs balance start -dusage=75 /mnt/cache

 

 

 

 

Hey,

 

I got sick of Windows 10 which i had previously been running as a VM, removed it and created a new Windows 7 VM from scratch. Since then i've had theses issues. Sometimes it will stay running for 12+ hours, sometimes 5 mins and it will pause.

 

I have been running VM's on unRAID for a LONG time and have never came across this issue before. Before i spend time reinstalling the VM from scratch is there anything else i can try.

 

Im only running 1 VM (Windows 7) + some dockers.

I have allocated 2 of my 4 cores to the VM.

I have allocated 8GB memory (16GB total) to the VM (79% used with everything running under load).

I have the VM on a 120GB cache drive (47GB free).

I have configured Windows to never sleep or turn off screen.

I have disabled hibernation.

 

Thanks in advance for your help.

 

 

Edited February 19, 2018 by N4TH4N
Updated with solution

[JorgeB]

The only time I've seen VMs pause is when running out of space, not the vdisk itself, but the device where the vdisk is stored, in doubt post your diags.

[N4TH4N]

Thanks, i'll try and get it to do it again and note the time so its easier to pin point in the diagnostics. I have 47GB free on the host disk.

[JorgeB]

If it's using btrfs the free space can sometimes be incorrectly reported and/or be fully allocated resulting in ENOSPC.

[N4TH4N]

It paused again, sometime since my last post.

unraid-diagnostics-20180217-2217.zip

[JorgeB]

The btrfs filesystem on your cache device is fully allocated, see here on how to fix:

 

https://lime-technology.com/forums/topic/62230-out-of-space-errors-on-cache-drive/?do=findComment&comment=610551

 

When done upgrade to v6.4 since this issue has been fixed on the newer kernels.

[N4TH4N]

root@unRAID:~# btrfs balance start -dusage=75 /mnt/cache
Done, had to relocate 50 out of 114 chunks
root@unRAID:~#

 

devid 1 size 111.79GiB used 85.79GiB path /dev/sdi1

 

I have downloaded and installed the 6.4.1, just waiting 20 mins for a copy to finish and ill reboot.

 

Thanks for the help, ill report back when i know the result. I do recall seeing devid at 111.79GiB used but just thought it meant the partition was using the whole disk. I had and still have no idea about how a BTRFS format drive works.

 

Is there anything else i'll need to do ?

 

 

 

 

[JorgeB]

 

Is there anything else i'll need to do ?

No, and updating to v6.4.1 should prevent it from happening again.

 

I do recall seeing devid at 111.79GiB used but just thought it meant the partition was using the whole disk.

It's the allocated amount, btrfs works differently than most file systems, first chunks are allocated, mainly for data and metadata and then those chunks are used, this issue happens on older kernels with SSDs, some unused or little used data chunks are not freed and when the filesystem tries to allocate a new metadata chunk fails resulting in ENOSPC.

 

 

[N4TH4N]

Much appreciated. My workflow can resume. I use the VM daily to do disk backups on client machines before formatting drives and reinstalling the OS. I have a few disk docks connected to a USB3 pcie card thats passthroughed to the VM. I had to revert back to a spare bare metal machine when the issue started.

[N4TH4N]

Really like the 6.4.1 update. Theres even a balance button for the BTRFS formatted drive.

[N4TH4N]

Can report that this has solved my VM issues.

[nt7561]

Hi everyone. I'm facing the same problem. I have 3 vms running (1 win10- no gpu passthrough, 1 homeassistant and 1 windows 10 with gpu passthrough) and some dockers. 

The vm with gpu passthrough, starts up but after I while gets paused. 

I have my vms on an 240gb ssd cache (120 gb used, 117 gb free). 

I'm also attaching my server's log. 

Could you please advice how to resolve this problem, since the vm is used to display info of my home automation system (as a kiosk display)? 

tower-diagnostics-20220805-1736.zip

[sirhotness]

i'm having this same issue all of a sudden on 6.12.8.  i'm running 2 vms, one windows, one linux, but my win10 keeps pausing.  i have both running on a 512g ssd cache with 50% free.  i just shut down the linux vm to see if this solves the issue.  i tried clicking on the above link in this post for how to solve, but it won't let me view the thread.

 

can someone let me know what to do in order to solve this problem?

 

as usual, thank you for all our help in advance.

[JorgeB]

Please post the diagnostics.
 

[pOpYRaid]

Same issue here on unraid 7 beta 2 and an windows 11 pro VM.
When i start it again after it's paused, it does'nt work and shows an  black screen with VNC.

 

Here are the diagnostics data: mediaserver-diagnostics-20240903-0808.zip

 

Ok, so the VM's are also living on the cache, which is the primary storage:

Edited September 3, 2024 by pOpYRaid

[SimonF]

Is the Vdisk filling up? Also check sleep options in VM.

[pOpYRaid]

34 minutes ago, SimonF said:

Is the Vdisk filling up? Also check sleep options in VM.

vdisk is not filling up inside VM. It's an KVM 64GB disk (allocated) and now are ~33GB free.

I had already the idea because of the sleep options inside the VM before i posted here and disabled them.

 

So will see how it goes...
 

 

[pOpYRaid]

@SimonFi think the issue was the sleep options in the VM. It now not paused for over ~24h.