paravirtual SCSI adapter (pvscsi) experience

[Atmos4]

Hi,

I wonder what's your experience with the new paravirtual scsi adapter (pvscsi) as compared to the calssic LSI Logic Parallel adapter (lsilogic)?

I found very little regarding this on the web, with the only benchmarks using insanely large arrays with EFDs.

Have you seen any real-world advantage in I/O performance (throughput, iops, latency) with the new adapter?

I have done some limited testing under W2K3 SP2 x86 with VMDKs on both local attached and iSCSI storage using IOmeter and have seen very little gains in throughput, but no real difference in CPU load or latency.

Regards,

Felix

[glynnd1]

I presume the purpose behind using using the EFD is to remove any possible array bottleneck out of the equation.

What iSCSI attached storage are you using? Could you be bottled necked on the iSCSI connection? Also, what IOmeter load are you running?

Just some thoughts.

[Atmos4]

Well, if the driver has lower overhead I should be seeing improvements, no matter how fast or slow the iSCSI storage is. I've been running 32k linear read and 8k 100% random 50/50 r/w IOmeter worksloads, the last one should simulate database access.