FS freeze after installing qemu guest agent - reproducible

[mailinglists]

Hi,

i just noticed that installing qemu guest agent can freeze VM.

This is how to reproduce it.

Create KVM VM. Set Qemu agent to Yes under options. Install Linux VM without Qemu Agent. Ran one or more automated backups, where PM tries to freeze VMs FS, but fails. Install qemu guest agent on VM. (I have also done some qm agent XXX pings alongside on host). Wait for guest V to freeze due to FS freeze order from host. Do a hard reboot of guest to bring it back.

It seems to me that there is a queue for qemu agent commands, which gets run even if qemu agent comes back a few days after agent commands were executed.

Should I submit a bug?

 

[dcsapak]

i do not think that is something that can be fixed, since the way the guest agent communicates is a serial terminal inside and socket on the outside
this simply stores the messages until somebody reads them

 

[mailinglists]

You could always submit a unfreeze FS command to the queue, if there is a freeze command waiting.

I have had the same problems in the past, when storage pool was overwhelmed and did not respond in time, so VMs just got locked and never unlocked.

 

[LnxBil]

I have had the same problems in the past,

Me too, yet nowadays is was reduces to several tries yet eventual success. In the old days, the VM lost its storage connection and the client crashed due to missing storage.