[CentOS] RAID on Email Server

Sat Oct 11 02:32:15 UTC 2008
Guy Boisvert <boisvert.guy at videotron.ca>

Matt wrote:
> 
> Right now its running pretty good but here it is.
> 
> 10:10:04 AM       CPU     %user     %nice   %system   %iowait     %idle
> 10:20:01 AM       all     13.87      0.00      2.45     59.20     24.49
> 10:30:03 AM       all     22.26      0.00      3.68     53.51     20.54
> 10:40:01 AM       all     20.58      0.00      3.78     55.40     20.24

[ Stuff Deleted ... ]

> 01:00:01 PM       all     11.53      0.00      2.38     20.96     65.12
> Average:          all     17.49      0.00      4.03     46.29     32.19
> 
> A while after the reboot it straightened its self out.  Yesterday "w"
> was indicatining load average of like 120 or more at times.  Today
> after reboot all is good.
> 
> Matt

Hi Matt,

Your %iowait seems high.

I had %iowait comparable to you with a single 200 Gigs 7200 RPM IDE drive.

Now we've upgraded this server: Opteron 2216 with 4 Gigs RAM, CentOS 64 
v5.2) and an Adaptec 3405 plus 4 x 73 Gigs Seagate 15K RPM (RAID 10). 
No more %iowait!  I benched it at about 140 MB/s and random r/w are very 
good on these drives.

We have 55 employees running Outlook connecting to Communicate with 
MAPI.  The dataset is about 100 Gigs.  Communigate use MBOX files for 
storage.


Guy Boisvert, ing.
IngTegration inc.