On Tue, Mar 6, 2012 at 10:07 PM, Reeted<address@hidden> wrote:
On 03/06/12 13:59, Stefan Hajnoczi wrote:
BTW, I'll take the opportunity to say that 15.8 or 20.3 k IOPS are very low
figures compared to what I'd instinctively expect from a paravirtualized
block driver.
There are now PCIe SSD cards that do 240 k IOPS (e.g. "OCZ RevoDrive 3 x2
max iops") which is 12-15 times higher, for something that has to go through
a real driver and a real PCI-express bus, and can't use zero-copy
techniques.
The IOPS we can give to a VM is currently less than half that of a single
SSD SATA drive (60 k IOPS or so, these days).
That's why I consider this topic of virtio-blk performances very important.
I hope there can be improvements in this sector...
It depends on the benchmark configuration. virtio-blk is capable of
doing 100,000s of iops, I've seen results. My guess is that you can
do>100,000 read iops with virtio-blk on a good machine and stock
qemu-kvm.