disk i/o busy

DotHQ · 06-07-2006, 12:48 PM

Hi,
I have an issue with disk i/o wait. My disk I/O wait percentage will slowly raise (after a reboot) over the course of a few days up to 20%. If I try to read or copy data from the SAN things are extremely slow. We're running RHEL AS3.0 update 5. We use qlogic 2340 HBA cards to connect to the SAN.
I don't know that this is a Linux or RH issue. It very well could be a HBA or SAN issue. If you know of a SAN forum (Dell EMC hardware) that might be good to post on please post a link here.

Thanks!

syg00 · 06-08-2006, 06:22 AM

Could be the hardware, can't help there.
If you were at a 2.6 kernel, maybe you could have tried playing with the I/O scheduler.
Maybe have a look at this for some light background reading.

DotHQ · 06-08-2006, 08:57 AM

Thanks for the reply.
Due to application & DB constraints we are stuck with the currrent kernel for awhile longer darnit.

We have a problem call in to Dell on it, but was hoping if someone else ran into this type of issue we might move things along a little quicker.

syg00 · 06-08-2006, 09:06 AM

Maybe you could occupy yourself with something like iostat - Jeremy has done an article on it here - see this
There was also a redhat (admin ???) paper about it a while back.