topic Re: Heavy disk I/O in Operating System - Linux

Heavy disk I/O

Jagadesh_2 — Thu, 13 Oct 2005 08:30:45 GMT

Dear All,
Sorry for posting this in HP forum... any how this is related to performance, hence you can help me in this.

I have an AIX server. It is showing heavy disk activity (nearly 100%) for some point of time and the wait queue is also increasing. The CPU idle is also gradually reducing. I wanted to know which is causing the heavy disk I/O. It is an OS disk, mirrored. I am not able to find any stale partitions. The disk is good.

The users use this application to log a call (Remedy Application). Please also let me know, whether network is involved for this heavy disk I/O. If so, how to check and rectify the same.

Many Thanks
S.Jagadesh

Re: Heavy disk I/O

Gopi Sekar — Thu, 13 Oct 2005 23:08:17 GMT

One reason could be the RAM, if the kernel runs out of RAM then it will start using the swap memory (which is hard disk memory).

This will create more IO activity especially if your system is running multiple applications (all of them are active) simultaneously.

check the memory usage and if swap usage is more then increase the RAM.

other reason could be the application might be calling lot of disk IO operations, in that case we can not do anything on the kernel.

Hope this helps,
Gopi

Re: Heavy disk I/O

Jagadesh_2 — Fri, 14 Oct 2005 04:45:18 GMT

The size of physical memory is 6GB and the Swap configured for this system is 20GB. The disk which is causing heavy i/o is the OS disk. Paging is configured on this disk.

The i/o or paging is happening rarely. Not all the time. One thing which i need to find out is which process is causing this.

How to find out which process is using more paging.

Thanks