[Qemu-devel] Migration debugging with different transport protocol

[Andrii L]

Hello,

Periodically, while migrating some virtual machines I experience the following errors:

qemu: warning: error while loading state for instance 0x0 of device 'ram'

qemu: warning: error while loading state section id 1

From reading Qemu mailing lists I understood that these errors can happen for various reasons. I tried using different Qemu versions from 1.0 to the trunk. And yes, I specify the same CPU, RAM, disk and ballooning info from both sides.

I applied the patch written by Alexander Graf https://lists.gnu.org/archive/html/qemu-devel/2013-10/msg02950.html to understand the process better. But it seems to work only for the exec migration method:

(qemu) migrate "exec:cat > mig"

Is it possible to debug Qemu TCP migration? For example, I am starting migration to remote host as:

(qemu) migrate -b tcp:192.168.1.1:4444

My goal is to have a clear picture in understanding the migration failures.

I would appreciate any advice. Thank you.