Pam Ochs <[email protected]> writes: > I'm looking for wisdom and advice here. > I'm supporting an application running on Solaris, and it is > experiencing performance problems during peak use times. I was asked > to look at the OS and ascertain where the issue might be. If this was
First thing I'd check for is iowait. look at top (or vmstat or sar or whatever) and first, is there any idle cpu time? id? if no, do you see iowait? (on top on my linux box, iowait is labled wa) here is a writeup I did for a client who was having a hard time determining if swap was causing problems (they were alarming when swap was used; I was pointing out that swap is only a problem if you are swapping in or swapping out) http://book.xen.prgmr.com/mediawiki/index.php/Do_I_have_enough_ram (I need to add some stuff on 'free' and the +-buffers line; the same client complains to me when 'free' reports low 'free' memory (when in fact it's all used as disk cache, as it should be. I think I've trained them to look at +- buffers before calling me, but it's good, related 'basic *nix admin' stuff) if you do have idle cpu time (when you are having the problem) then the problem is elsewhere. Sometimes that even means the application is insifficently multithreaded. Not saying that's the problem, but it's the first thing I always check. another thing to do is ping it from outside your network while the problem is occuring. If your pipe is full, you will see longer ping times than usual. _______________________________________________ Discuss mailing list [email protected] http://lopsa.org/cgi-bin/mailman/listinfo/discuss This list provided by the League of Professional System Administrators http://lopsa.org/
