Tuesday, May 27, 2008

Perc 5/i performance - improvement with blockdev

I've not been pleased with performance...Disk io is definitely the bottleneck. The %wa or io wait in top is always high when the system is sluggish, slow. Of course, I'm usually doing a lot of disk io so it is not expected. But I did find the following site that talks about performance on the Perc controller



blockdev --getra /dev/sda

and received 256


blockdev --setra 8192 /dev/sda

Initial tests of suspending/resuming vms and copying show significant improvement.

Added the line

/sbin/blockdev --setra 8192 /dev/sda

in /etc/rc.local

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