Virtual machine cannot be started

Apps and Virtualization
1

I just upgraded from TrueNAS SCALE 24.10 to 25.10, and everything is generally good except for some issues with the virtual machines. I have two virtual machines running well in 24.10, but after upgrading to 25.10, one virtual machine running Home Assistant works fine, while the other virtual ma

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screenshot_20251210_0704401342Ɨ1200 182 KB

chine running OpenWrt fails to start and reports an error. How can I resolve this issue? Thank you.

2

Thatā€™s really weird.
Could you check, if the kvm module is actuall loaded (lsmod | grep kvm) and if yes (which I suppose it is), check the qemu process of the currently running vm to see if it actually uses kvm ( ps aux | grep qemu | grep -o 'accel kvm')?
Both should basically always be the case but if they are your error message makes basically no sense.

3

Thanks a lot for helping.I checked kvm module in the truenas scale system,and the result was:

#lsmod | grep kvm
kvm_intel   417992 10
kvm 1392640 7 kvm_intel
irqbypass 12288 1 kvm

 #ps aux | grep qemu | grep -o 'accel kvm'
 accel kvm

and then I checked in the running virtual machine,the result was nothing.

4

the result seems to have been as expected ā€œaccel kvmā€ - so the currently running vm is indeed using kvm.
Iā€™d suggest opening a support ticket - this does not make any sense to me.
If you donā€™t care about finding the root cause though you could probably just note how the vm was configured (if you need the same mac address for example, write that down, also CPU/RAM/NIC configā€¦), delete the vm without deleting itā€™s data and create a new VM with the old disk(s). I think that will probably work.

5

I created a new VM with the old disk and tried to create a new VM with loading new image,but the same result.

Thanks a lot!

6

It gets weirder and weirder. Have you compared the config of the working vm to the non-working ones?

7

Finally, I discovered a pattern: after restarting the TrueNAS system, all virtual machines run normally. However, if a virtual machine is manually stopped, it can no longer be started, and similar errors occur.

8

Sorry I really canā€™t wrap my mind around that. A bug report would probably be best.

9

Thank you for your kind help. I think I will report this issue. Thank you again.

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