[libvirt-users] libvirt with persistent device names

[Jan Marquardt]

Hi,

I am trying to create a logical volume storage pool with persistent
device names for the block devices, because I can't/don't want to ensure
that /dev/sd* names are persistent through reboots.

virsh # pool-define-as web2067 logical - -
/dev/disk/by-path/pci-0000:18:00.0-scsi-0:2:2:0 web2067 /dev/web2067
virsh # pool-build web2067

These two steps work as expected and the pv and the vg get created, but
when I try to start the pool I get the following error:

virsh # pool-start web2067
error: Failed to start pool web2067
error: unsupported configuration: cannot find any matching source
devices for logical volume group 'web2067'

If I do the same steps just with /dev/sdX instead of
/dev/disk/by-path/..., the pool gets created correctly.

This looks like a bug for me or am I wrong? If this is the case, is this
and known issue and fixed in later versions?

I am running Ubuntu 18.04 with libvirt in version 4.0.0.

Best Regards

Jan

[Daniel P. Berrangé]

Post by Jan Marquardt
Hi,
I am trying to create a logical volume storage pool with persistent
device names for the block devices, because I can't/don't want to ensure
that /dev/sd* names are persistent through reboots.
virsh # pool-define-as web2067 logical - -
/dev/disk/by-path/pci-0000:18:00.0-scsi-0:2:2:0 web2067 /dev/web2067
virsh # pool-build web2067
These two steps work as expected and the pv and the vg get created, but
virsh # pool-start web2067
error: Failed to start pool web2067
error: unsupported configuration: cannot find any matching source
devices for logical volume group 'web2067'
If I do the same steps just with /dev/sdX instead of
/dev/disk/by-path/..., the pool gets created correctly.
This looks like a bug for me or am I wrong? If this is the case, is this
and known issue and fixed in later versions?

We expect /dev and /dev/disk/by-path to both work to the same extent,
so yes, that certainly sounds like a valid bug to me. I'm not aware of
it being reported or fixed before.


Regards,
Daniel

[Jan Marquardt]

Post by Jan Marquardt
I am trying to create a logical volume storage pool with persistent
device names for the block devices, because I can't/don't want to ensure
that /dev/sd* names are persistent through reboots.
virsh # pool-define-as web2067 logical - -
/dev/disk/by-path/pci-0000:18:00.0-scsi-0:2:2:0 web2067 /dev/web2067
virsh # pool-build web2067
These two steps work as expected and the pv and the vg get created, but
virsh # pool-start web2067
error: Failed to start pool web2067
error: unsupported configuration: cannot find any matching source
devices for logical volume group 'web2067'
If I do the same steps just with /dev/sdX instead of
/dev/disk/by-path/..., the pool gets created correctly.
This looks like a bug for me or am I wrong? If this is the case, is this
and known issue and fixed in later versions?
I am running Ubuntu 18.04 with libvirt in version 4.0.0.

For the record: This issue was not a libvirt issue. It's a lvm
configuration issue. Thanks to Christian over at Ubuntu Launchpad for
pointing that out.

https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1801918