Rhe:iowait

mastermatics · 08-25-2006, 09:22 AM

I run a REDHAT Enterprise version server which is used as a hosting server with around 200 domains setup on it, of late i have noticed that the IOWAIT is taking up a lot of resources therby pushing up the CPU load to 2.5+ and sometimes going up to even 9.0.
I have ClamAV and Spamassassin installed besides the ususal PHP,MySQL.
Can anyone suggest whats the cause for a high IOWAIT and what steps needs to be taken to reduice this.

thnx
samir

syg00 · 08-26-2006, 02:35 AM

Mmmm - I/O maybe ???.
I don't understand what you mean by this ...

Quote:

of late i have noticed that the IOWAIT is taking up a lot of resources therby pushing up the CPU load to 2.5+ and sometimes going up to even 9.0.

The load ave is (at best) only a poor indicator of work queued for CPUs. If you have a lot of IOWAIT, it's even worse.
Best to concentrate on sorting out your disk farm - RHEL should include the sysstat package - check the admin guide for some pointers on what to look for.

Actually I seem to remember a thread a while back about a problem just like this on RHEL - try a search here on LQ.

mastermatics · 08-26-2006, 06:18 AM

Thnx Syg00, i meant I/O as you rightly pointed out.
I will check the fdisk output to see if it throws up anything.
I did check out the other psots on this topic, but it wasnt too helpful, hence created a new thread.
Actually the server was running fine till a few weeks back, when we installed a chkusr patch basically to delete mails not intended for recepients on the server, thats when the CPU started showing increased loads. My admin guys tell me the qmail-scanner could be a probable cause, i dunno, i am pretty lost out here, since the server is 2.5 yrs old and hasnt given any trouble so far

thnx
samir