[CentOS] Poor RAID performance new Xeon server?
lists at pinkyboots.co.uk
Sun Jan 11 15:13:13 UTC 2009
William Warren 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
>> 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
>> # bonnie++ -s 256m -d /mnt -u 0 -r 0
>> # 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
>> Plus I am hoping to run some virtualised guests on it eventually, but
>> nothing too heavy.
>> CentOS mailing list
>> CentOS at centos.org
> That onbard raid is fakeraid..so when you dialup raid 5 you effectivly
> put hte hdd's in pio mode since ALL data has to be routed through your
> cpu. Please get a raid card from HP or go get a 3ware card so you ahve
> real hardware raid.
> fake and real raid chpsets:
> Why using fakeraid at all is bad:
> MDM under linux is kernel raid that does not use a binary
> driver..however you don't want to do ANY software raid 5.
I am no expert on RAID, so you have opened my eyes to somethings I
wasn't aware of.
I am considering disabling the onboard RAID in the BIOS and
re-installing CentOS and configuring the 4 drives as RAID 10 just to see
what the performance is like.
Or I may purchase a card as you advise. Would I benefit from buying a
SCSI/or SAS card and drives for my requirements? Basically the main role
of the machine is to serve a ~600MB file via samba to 5 Windows XP cient
PC's on a gigabit network.
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