Comment 0 for bug 1505564

Hi,

Some of our nova compute hosts regularly freeze, sometimes for a few hours, with kern.log getting spammed with :
block nbdX: Attempted send on closed socket

and a few "CPU soft lockup" messages (see attached log). This clears up when the queue gets cleared, eg :
block nbdX: queue cleared

trusty hosts with kernel version 3.19.0-30-generic.

Note that timestamps from kern.log appears to be wrong, it looks like the messages are being held, and then all delivered at once when the kernel unfreezes.

Attaching apport files from 2 hosts below.