Re: [ovirt-devel] Issue: Device path changed after adding disks to guest VM

On Wed, Jan 06, 2021 at 17:16:24 +0200, Nir Soffer wrote: > On Wed, Dec 2, 2020 at 4:57 PM Joy Li <joooy.li(a)gmail.com&gt; wrote: [...] > Comparing to state before reboot: > > # virsh -r domblklist disk-mapping > Target Source > --------------------------------------------------------------------------------------------------------------------------------------------------------------- > sdc - > sda /rhev/data-center/mnt/blockSD/84dc4e3c-00fd-4263-84e8-fc246eeee6e9/images/40018b33-2b11-4d10-82e4-604a5b135fb2/40f455c4-8c92-4f8f-91c2-991b0ddfc2f5 > vda /dev/mapper/3600140594af345ed76d42058f2b1a454 > vdb /dev/mapper/360014050058f2f8a0474dc7a8a7cc6a5 > vdc /dev/mapper/36001405b4d0c0b7544d47438b21296ef > > # ls -lh /dev/disk/by-id/virtio-* > lrwxrwxrwx. 1 root root 9 Jan 6 09:42 > /dev/disk/by-id/virtio-b97e68b2-87ea-45ca-9 -> ../../vda > lrwxrwxrwx. 1 root root 9 Jan 6 09:42 > /dev/disk/by-id/virtio-d9a29187-f492-4a0d-a -> ../../vdb > lrwxrwxrwx. 1 root root 9 Jan 6 09:51 > /dev/disk/by-id/virtio-e801c2e4-dc2e-4c53-b -> ../../vdc > > In the guest disks are mapped to the same device name. > > It looks like libivrt domblklist is not correct - vdb and vdc are switched. > Peter, this expected? The names in 'virsh domblklist' are unfortunately and confusingly chosen to match the expected /dev/ device node name, but it's at kernel's discretion to name /dev/ nodes. This means that it's not guaranteed that what you see in 'virsh domblklist' will match the state in the guest.