%disk time opinion requested

[timc]

Trying to deal with a user complaint of slowness. Many variables looked at which look normal (Buffer cache, queue length,memory). Probably looks like a network issue. My question is what people consider acceptable when it comes to %disk time. My %disk time has increased from an average of 20% to 33% in recent months. My average disk read and average disk write have both been less than one. MY research has showed that more than 55% %disk time for ten minutes is considered a problem. Not there yet but seem to be slowly getting there. THe app running against my server is vendor written so can't change, also running log shipping which is probably inflating the numbers a little.
Any opinions appreciated.

[skhanal]

Also monitor disk idle time, this gives another perspective for disk utilization. I had read somewhere that disk time may be misleading.

Did you check disk queue length? Also see the server if any disk in the RAID is faulty.