How to reduce IOWAIT in linux

UNIX for Advanced & Expert Users
1

Hi All,

Any ideas how to reduce IOWAIT and increase disk speed on Linux server.

Server has 4 CPUs and with 8GB RAM.

Thanks in advance,

Regards,
Bache

2

Not knowing much about your machine here are a few thoughts.

  1. Are you using the fastest disks you can, both rotational speed and transfer speed and can your disk controllers support the transfer rates?

  2. Consider having a number of disks so binaries live on different disks to data. This will reduce the time spent waiting for seeks to occur.

  3. In certain configurations, a RAID arrangement may speed up access to disks.

4, Are you using delayed writes?

3

Here is an interesting article regarding performance tweaks for Linux...

http://www.linux.com/feature/116693

4

Another tool that will suggest good options is "iozone - filesystem benchmark tool".