[CentOS] software raid
feizhou at graffiti.net
Thu Mar 29 17:02:19 UTC 2007
chrism at imntv.com wrote:
> Feizhou wrote:
>> William Warren wrote:
>>> as soon as you goto software raid 5 you'll get a good performance
>>> hit. Head for the hardware raid cards then. You can get the 3ware
>>> ide cards for 150 or less now.
>> don't know if it is still the case but ext3 + 3ware + ext3 = ultra
>> slow. you'd want to use XFS or some other filesystem...
argh...i missed the raid5 on 3ware part.
> I keep hearing about this "slowness" thing. Here is a bonnie++ run on
> one of my spare machines. This particular machine is also running 4
> copies of Folding at Home in the background during the test. The array
> being tested is on a 3Ware 9550 card with 8 500gig barracudas. The
> filesystem is a standard ext3 filesystem with zero tweaks. It doesn't
> appear that slow to me, but perhaps I'm just easy to please.
<shrug> You are free to not believe or to believe. Maybe the latest
Centos 4 kernel has a fix or something but ext3 + 3ware raid5 = slow
while XFS would fly. Are your 8 500GB configured in raid5 or raid10? If
it is raid10, then yes, it will fly. You switch to raid5 however and you
will experience a slow down. This is not limited to 3ware boards lower
than 95xx which suffer from lack of onboard memory to make things fly.
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