On Fri, 17 Aug 2007, Mag Gam wrote:
On 8/17/07, John R Pierce pierce@hogranch.com wrote:
Mag Gam wrote:
I have a server with 2 HBAs, and the users keeps complaining about performance problems. My question is, how can I relate the process with high I/O wait? Also, is it possible to see how much data is being pushed thru by my 2 HBAs?
iostat (part of the sysstat package) will answer your 2nd question.
I dunno how to measure io wait time per process. maybe IBM's NMON can do that, not sure, I haven't used it for a while. http://www-941.haw.ibm.com/collaboration/wiki/display/WikiPtype/nmon
Thanks John.
Yes, this is a tricky question, but I face this a lot....Unfortunately, I am not sure how to check the adapter throughput, and what process is causing the i/o wait.
I believe that recent kernels have a patch applied that show io counters per process. I haven't looked into it yet though.
This is one of the most important items on my wishlist for dstat, a topio plugin next to the existing topcpu and topmem plugins.
Kind regards, -- dag wieers, dag@wieers.com, http://dag.wieers.com/ -- [Any errors in spelling, tact or fact are transmission errors]