[Xen-devel] PHY vs. VD benchmark

["Tvrtko A. Uršulin" <tvrtko@xxxxxxxxxxxx>]

I did some quick benchmarks in case somebody is interested. Few words about 
the setup:

DOM1 64Mb RAM, vd:1 (4Gb on real /dev/sdb)
DOM2 64Mb RAM, sda1 (4Gb mapped from real /dev/sdc5)

sdb is configured with only two VD's (4Gb root + 128Mb swap) so that in both 
cases partitions lay at the beginning of the physical disk. I suspect at 
least, because I don't know how VD code allocates space. sdc also has only 
two phy partitions with the same setup.

Both have identical root fs-s.

Single run is done while other domains sit idle.
Concurrent run is both domain running bonnie++, well, concurrently :)

It seems that phy is significantly faster than vd, and that concurrent i/o 
load on separate disks doesn't  hurt performace.

Detailed log attached.

Attachment: bonnie-phy-concurrent.log
Description: Text Data

Attachment: bonnie-vd-single.log
Description: Text Data

Attachment: bonnie-phy-single.log
Description: Text Data

Attachment: bonnie-vd-concurrent.log
Description: Text Data