Subject: Re: kernel driver support for Dell 5/iR raid controller
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Pierre-Philipp Braun <pbraun@nethence.com>
List: tech-kern
Date: 06/27/2007 20:57:24
Hi Quentin and Manuel,

Quoting Manuel Bouyer (27/06/2007 20:21),
>> bsdp# time dd if=/dev/zero of=lala.zero count=100 bs=1024k
>> 100+0 records in
>> 100+0 records out
>> 104857600 bytes transferred in 7.251 secs (14461122 bytes/sec)
>>         7.26 real         0.00 user         0.34 sys
> 
> What kind of disk and array do you have ? On dell 2950 I get about 70/80MB/s
> on a raid5 array.

two SAS attached disks (no more info from home), 140GB each, as RAID-1.

> Do you have the battery backup for the cache ?

??? I don't know

>> bench.sh:
>> #!/bin/sh
>> time dd if=/dev/zero of=lala.zero count=100 bs=1024k &
>> time dd if=/dev/zero of=lala2.zero count=100 bs=1024k
>> rm lala.zero
>> rm lala2.zero
> 
> I suspect with this, you only check the memory bandwidth of the system.
> The data may not reach the disk at all.

I remember a tar xjf pkgsrc.tar.bz2 took ages, I had to stop it.