Which process are waiting for I/O?

Dustin Puryear dpuryear at usa.net
Sun Aug 17 09:37:42 PDT 2003

At 02:28 PM 8/10/2003 -0700, Rus Foster wrote:

>Hi All,
>I've got a box which is getting high loads as process are starting waiting
>for I/O but I can't track down the process as I think they stop/start
>quickly. Any ideas of how to track it down?

Yes. You need to enable process accounting using accton:

# accton /var/account/acct

Let the processes that you suspect are causing issues run for a bit. Next, 
use sa to determine what the heck is going on. You can get a lot of detail 
out of sa so make sure to read the manpage. You may also want to run bsdsar 
(in ports) to watch for higher-level issues while using sa to get the real 

/var/account/acct is going to grow pretty fast. Be sure to rotate it if you 
plan on leaving process accounting enabled after your troubleshooting.

Dustin Puryear <dustin at puryear-it.com>
Puryear Information Technology, LLC <http://www.puryear-it.com>
Providing expertise in the management, integration, and
security of Windows and UNIX systems, networks, and applications.

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