[Pkg-ganeti-devel] Bug#782123: ganeti: Does not clean up on failed migrations

[Joerg Jaspert]

Package: ganeti
Version: 2.11.6-1~bpo70+1
Severity: important

Dear Maintainer,

this at least happens with the extstorage interface and the bug from
me yesterday, #782073, though it appears it may happen with all
failures pre-migration: Ganeti does not clean up.

In this case it does not undo the disk changes done (which led to the
other bug), so the exported disk is still on the host it had selected
when trying the last migration.

At a minimum this is unclean - having the disks exported to two hosts
all the time can lead to errors - but it also refuses to work with
migrations later on: Should the hbal command select the same ganeti
host for the VM where a pre-migration failed earlier on, even though
the host is fine now to take the VM[1], this particular VM will always
fail. As the disk is already exported, another attaching fails (as the
attach sensibly just tells "here is the disk already", not redoing the
attaching).

IMO Ganeti should, on failed migrations, run all the commands
neccessary to undo whatever actions it already took. At least up to
the point where the actual migration (memory transfer & co) starts.


[1] in this case no longer so many md devices around, and other VMs
migrate easily to it

-- 
bye Joerg