[ovirt-users] VirtIO-SCSI and viodiskcache custom property

[Matthias Leopold]

Hi,

is there a reason why the viodiskcache custom property isn't honored 
when using VirtIO-SCSI?

On a Cinder (Ceph) disk "viodiskcache=writeback" is ignored with 
VirtIO-SCSI and honored when using VirtIO.

On an iSCSI disk "viodiskcache=writeback" is ignored with VirtIO-SCSI 
and the VM can't be started when using VirtIO with "unsupported 
configuration: native I/O needs either no disk cache or directsync cache 
mode, QEMU will fallback to aio=threads"

We actually want to use "viodiskcache=writeback" with Cinder (Ceph) disks.

oVirt version: 4.1.8

Thanks
Matthias