Resuming a suspended VM does not write anything to the console log. console.log is empty

[JB]

In Essex version (both 2012.1 and 2012.1.3), when I suspend and resume a running VM, I do not see anything in the console log of the VM. I see that when it suspends it wipes out the log and resume does not write the complete log. Usuallly, I depend on this log to see if the networking worked and if the metadata server worked. Though I do not see anything console log, after resuming the VM, I am able to ping and ssh without any problems.

[Davanum Srinivas (DIMS) (dims-v)]

I can see this problem in latest master as well

[Rafi Khardalian (rkhardalian)]

It's actually the resume which is wiping out the console log, not the suspend. The reason is that the qemu/kvm process is stopped completely during a suspend. On resume, the console log is being truncated rather than appended. I'll take a look to see if we have any options for changing this behavior, or whether this is ultimately a libvirt change.

[Rafi Khardalian (rkhardalian)]

There doesn't appear to be anything we can do configuration wise to append to the log. I see two options:

a) We can open a bug with the libvirt folks to add support for appending to these logs.

b) Do something creative in the Nova libvirt driver to move logs around during suspend/resume (i.e. mv console.log console.log.1), then concat them when returning a console log request (yuck).

Thoughts?

[Davanum Srinivas (DIMS) (dims-v)]

+1 to option a)

[Vish Ishaya (vishvananda)]

looks like this needs to be proposed against libvirt.