[CentOS] Poor RAID performance new Xeon server?

Stewart Williams lists at pinkyboots.co.uk
Sun Jan 11 15:08:02 UTC 2009


John R Pierce wrote:
> Stewart Williams wrote:
>> I have just purchased an HP ProLiant HP ML110 G5 server and install ed 
>> CentOS 5.2 x86_64 on it.
>>
>> It has the following spec:
>>
>> Intel(R) Xeon(R) CPU 3065  @ 2.33GHz
>> 4GB ECC memory
>> 4 x 250GB SATA hard disks running at 1.5GB/s
>>
>> Onboard RAID controller is enabled but at the moment I have used mdadm 
>> to configure the array.
>>
>> RAID bus controller: Intel Corporation 82801 SATA RAID Controller
>>
> 
> that is essentially desktop grade disk IO
> 
> 
>> For a simple striped array I ran:
>>
>> # mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sdb1 /dev/sdc1
>> # mke2fs -j /dev/md0
>> # mount -t ext3 /dev/md0 /mnt
>>
>> Attached are the results of 2 bonnie++ tests I made to test the 
>> performance:
>>
>> # bonnie++ -s 256m -d /mnt -u 0 -r 0
>>
>> and
>>
>> # bonnie++ -s 1g -d /mnt -u 0 -r 0
>>
>> I also tried 3 of the drives in a RAID 5 setup with gave similar results.
>>
>> Is it me or are the results poor?
>>
>> Is this the best I can expect from the hardware or is something wrong?
>>
>> I would appreciate any advice or possible tweaks I can make to the 
>> system to make the performance better.
>>
>> The block I/O is the thing that concerns me as mostly I am serving a 
>> 650MB file via samba to 5 clients and I think this is where I need the 
>> speed.
> 
> is this a sequential or random access application thats using this 
> file?   is it read only/mostly, or is it random update?

I'm not sure, how can I find this out?

> its rather hard to read your bonnie output logs as they aren't very 
> columnar. but it appears the sequetial read speed at least is really high.
> 
> i'm seeing 55MB/sec random(block) and 1.4GB/sec sequential reads on the 
> 1GB file,

Correct.

> so I dunno what your issues are...   of course, a 1GB file 
> sits entirely in the system cache assuming a reasonable amount of 
> otherwise idle memory

I'm not sure whether the performance would suffice as I've not tried 
putting it in production.

I am going to benchmark the old server (currently in production) that 
this is replacing.

Thanks,

Stewart


More information about the CentOS mailing list