OK VMs do work fine now. Sorry for missing the patch after switching to
qemu-kvm.
Am 09.08.2012 14:44, schrieb Paolo Bonzini:
Ok, try deadline in the guest then. Using noop amplifies bad
performance, because you lose request merging. With no host scheduler,
as is the case with libiscsi, noop is rarely a good idea.
Tests with cache=none and deadline:
virtio-scsi:
write: io=8267MB, bw=94023KB/s, iops=23505, runt= 90032msec
read : io=14576MB, bw=165783KB/s, iops=41445, runt= 90035msec
write: io=21312MB, bw=240782KB/s, iops=58, runt= 90636msec
read : io=48072MB, bw=544882KB/s, iops=133, runt= 90342msec
virtio-blk:
write: io=9210MB, bw=104710KB/s, iops=26177, runt= 90070msec
read : io=18804MB, bw=213929KB/s, iops=53482, runt= 90006msec
write: io=29080MB, bw=329478KB/s, iops=80, runt= 90379msec
read : io=26328MB, bw=298159KB/s, iops=72, runt= 90421msec
So this looks OK to me. Do you agree? So with virtio-scsi discard should
work?
Greets and many thanks
Stefan
