Could be the cause for T97047: EventLogging schemas are not served properly on beta cluster (which does not seem to be intermittent though).

This problem is still ongoing, although @coren and @Andrew may have found the root cause: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1346917

After updating the kernel on labvirt1001 and labvirt1002, the following guests may be problem free:

• deployment-bastion
• deployment-cache-text02
• deployment-elastic08
• deployment-lucid-salt
• deployment-memc03
• deployment-pdf01
• deployment-rsync01
• deployment-salt
• deployment-urldownloader
• deployment-cache-upload02
• deployment-db1
• deployment-eventlogging02
• deployment-mathoid
• deployment-memc04
• deployment-pdf02
• deployment-sca01
• deployment-videoscaler01

Overnight monitoring of those libvirt guests should tell us whether or not the root cause of the problem has been solved.

From T96905 it seems MySQL/MariaDB is not started on boot and deployment-db1 got rebooted on Thu Apr 23 23:53. I have restated MySQL :-)

This should be all fixed now; I'm not seeing the intermittent VM stalls anymore and all kernels have been upgraded to the fixed kernel.