On Jan 19, 2018 3:29 PM, "Matthias Leopold" < matthias.leopold@meduniwien.ac.at> wrote: 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. That's because on block storage we use native io and not threads. I assume the hook needs to change to use native io in this case. Y. oVirt version: 4.1.8 Thanks Matthias _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users