Nov 11, 2004
Last weeks, we have detected that the POP3 service is restarted frecuently by the chkservd service.

After install the munin graphs to investigate, we have detected that in the graphic of the CPU, the iowait is very hight (about 100% over 200%)

- We have upgraded our ram from 1 to 2Gb
- We have checked the RAID1 disks, it seems there isn't problems here
- We have trying to tune the courier-imap's values (up and down)
- Network graph seems to be ok

Nothing works, the iowait is still hight.

(The rest of the services seems that works fine)

Any idea ?????

Our server info:

- Intel(R) Pentium(R) D CPU 3.00GHz
- 2Gb RAM
- RAID1 by hardware (2x220Gb)
- WHM 11.15.0 cPanel 11.18.3-S21703
- CENTOS Enterprise 4.6 i686 on standard - WHM X v3.1.0
- Linux kernel 2.6.9-55.0.2.ELsmp
Last edited:


Well-Known Member
Verifed Vendor
Jun 15, 2002
Go on, have a guess
High IOWAIT usually means that you have a disk hungry process running. Are the backups running when you're seeing high IOWAIT? Have you checked top and the ps list incase there are any looping processes?