Good morning folks, and thank you in advance.
I am working on migrating my oVirt backing store from NFS to iSCSI.
oVirt Environment:
oVirt Open Virtualization Manager
Software Version:4.4.4.7-1.el8
TrueNAS environment:
FreeBSD truenas.local 12.2-RELEASE-p11 75566f060d4(HEAD) TRUENAS amd64
The iSCSI share is on a TrueNAS server, exposed to user VDSM and group 36.
oVirt sees the targeted share, but is unable to make use of it.
The latest issue is "Error while executing action New SAN Storage Domain: Volume Group block size error, please check your Volume Group configuration, Supported block size is 512 bytes."
As near as I can tell, oVirt does not support any block size other than 512 bytes, while TrueNAS's smallest OOB block size is 4k.
This is correct, oVirt does not support 4k block storage.
I know that oVirt on TrueNAS is a common configuration, so I expect I am missing something really obvious here, probably a TrueNAS configuration needed to make TrueNAS work with 512 byte blocks.
Any advice would be helpful.
You can use NFS exported by TrueNAS. With NFS the underlying block size is hidden
since direct I/O on NFS does not perform direct I/O on the server.
Another way is to use Managed Block Storage (MBS) - if there a Cinder driver that can manage
your storage server, you can use MBS disks with any block size. The block size limit comes from
the traditional lvm based storage domain code. When using MBS, you use one LUN per disk, and
qemu does not have any issue working with such LUNs.
Check with TrueNAS if they support emulating 512 block size of have another way to
support clients that do not support 4k storage.
Nir