VM Crashed had to reboot

A

amitp123

New Member
Jun 16, 2025
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Hi Team

We had a VM that crashed this morning , no response from keyboard, mouse via ssh completely frozen so had no choice to reboot it.
Is there commands we can to or get a crash dump setup so we can see what caused it?

Looks like the CPU just went to 100% and crashed.

Many Thanks
Amit
 
Hi,
you can check the host's and guest's system logs from around the time the issue happened. Please also share the output of pveversion -v and qm config ID with the numerical ID of the VM.
 
Hi Fiona

Please find attached output you requested.


The host isn't showing anything we can see that caused a vm to crash.
The VM this is the entry i get from syslog before crash happened.

Feb 10 17:27:17 k8s-mol-fe-cp-a01 kubelet[1296]: E0210 17:27:17.455896 1296 dns.go:153] "Nameserver limits exceeded" err="Nameserver limits were exceeded, some nameservers have been omitted, the applied nameserver line is: 10.253.0.11 10.253.0.12 10.253.0.11"
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At this stage we rebooted the VM.
 

Attachments

The log seems corrupted, also hinting at a crash. If there is nothing in the host's logs it might point to an in-guest issue. Two things to note about the VM configuration: I'd recommend using VirtIO SCSI single as the SCSI controller and enable the IO Thread setting on the disks. CPU hotplug is activated, did you hotplug any CPUs before the crash happened?

What OS/kernel is running inside the guest?
 
Morning fiona sorry for late reply.

No CPU's added before the crash 100% sure as the VM has been running fine for 3 wks no issues.

ubuntu 22.04 OS inside the guest vm.

The CPU hotplug this vm was imported from esx so would have kept the original settings.

Is there a way we can capture the crash or configure it?

Regards
Amit
 
You could try using something like kdump inside the guest to capture the crash, but it is a bit involved. An easier way is to run journalctl -f via ssh from the host (or another machine) to monitor the logs and hope to retrieve more information.

Are you running the latest version of the guest kernel?
 
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