On Fri, Apr 15, 2022 at 16:58:08 +0200, Valentijn Sessink wrote: > Hi list, > > I'm trying to migrate a few qemu virtual machines between two 1G ethernet > connected hosts, with local storage only. I got endless "error: operation > failed: migration of disk vda failed: Input/output error" errors and > thought: something wrong with settings. > > However, then, suddenly: I succeeded without changing anything. And, hey: > while ! time virsh migrate --live --persistent --undefinesource > --copy-storage-all ubuntu20.04 qemu+ssh://duikboot/system; do a=$(( $a + 1 > )); echo $a; done > > ... retried 8 times, but then: success. This smells like a race condition, > doesn't it? A bit weird is the fact that the migration seems to succeed > every time while copying from revolving disks to SSD; but the other way > around has this Input/output error. > > There are some messages in /var/log/syslog, but not at the time of the > failure, and no disk errors. These disks are LVM2 volumes and they live on > raid arrays - and/so there is not a real, as in physical, I/O-error. > > Source system has SSD's, target system has regular disks. > > 1) is this the right mailing list? I'm not 100% sure. > 2) how can I research this further? Spending hours on a "while / then" loop > to try and retry live migration looks like a dull job for my poor computers > ;-)
It would be helpful if you provide the VM XML file to see how your disks are configured and the debug log file when the bug reproduces: https://www.libvirt.org/kbase/debuglogs.html#less-verbose-logging-for-qemu-vms Without that my only hunch would be that you ran out of disk space on the destination which caused the I/O error.
