[OpenAFS] Speed difference between OpenAFS 1.4.x on Debian and CentOS

[Michał Droździewicz]

Hello all,
Recently I've spent some time testing speed of OpenAFS server 
installation on different machines and operating systems.

First I've tried to install OpenAFS with Debian 4.0 (etch) on 3 
different machines (beginning from old Celeron, through Pentium 4 and at 
the end on Xeon 3GHz). Speed was pretty much the same when coping files 
from local disk to AFS (transfer without the network). It was about 8 to 
9 MiB/s and it didn't depend on machine RAM memory nor processor power). 
Tuning the afs client haven't helped at all (speed was rather dropping 
than going up).

Second I've taken the strongest computer (with Xeon and 4GiB of RAM) and 
installed on it CentOS 5 and OpenAFS 1.4.6 using RPM-s from openafs.org. 
And what was my surprise, when transfer from local disk to afs structure 
was like 35-50MiB/s. Over a 100Mib network it was 12MiB/s and over a 
1000Mib network it was around 25MiB/s.

Lets say that the performance was like 250% better with 1.4.6 on CentOS 
5 than with 1.4.2 on Debian 4.0. I've even compiled 1.4.6 and 1.5.34 on 
Debian 4.0 but performance was the same.

Could somebody please explain to me how this is even possible and what 
to do to get the same speed on Debian that I've got on CentOS. Because 
in our company we prefer to use Debian (company policy) and mixing in 
new linux distribution isn't the greatest idea ever.

Thanks in advance.

-- 
Mike D.