SQLIO stats on Hyper-V host


  • I've been using sqlio.exe to benchmark a new ssd drive and I get much higher results running it in a Hyper-V VM compared to the physical host, much higher.

    For example, on the raw host I get 2000 IOPS, on the VM I get 5000 etc.

    When I compare the physical disk stats in perfmon when the test is running it appears that the VM is writing at a rate of about 250MB/sec, while the host is only writing about 60MB/sec.

    I'm using a 20GB datafile in the test to ensure nothing gets cached in memory etc and I know its writing to disk based on the host's perfmon counters.


    Any ideas why I'm getting artificially high results in the VM?


    Friday, October 15, 2010 9:02 PM