There is another issue, which is currently failing all CQ, and its related to the new IBRS CPU model.

It looks like all of the lago slaves were upgraded to new Libvirt and kernel on Friday, while we still don't have a fix on lago-ost-plugin for that. 

I think there was a misunderstanding about what to upgrade, and it might have been understood that only the bios upgrade breaks it and not the kernel one.

In any case, we're currently fixing the issue, either by downgrading the relevant pkgs on lago slaves or adding the mapping to new CPU types from OST.

For future, I suggest a few updates to maintenance work on Jenkins slaves ( VMs or BM ):

1. Let's avoid doing an upgrade close to a weekend ( i.e not on Thu-Sun ), so all the team can be around to help if needed or if something unexpected happens.

2. When we have a system-wide upgrade scheduled, like all BM slaves or VMs for a specific OS, let's adopt a gradual upgrade with a few days window in between, 

  e.g, if we need to upgrade all Lago slaves, let's upgrade 1-2 and wait to see if nothing breaks and continue after we verify OST runs ( either seeing on CQ or running manually ) 

Thoughts?