On Jul 28, 2010, at 8:34 AM, Roy Sigurd Karlsbakk wrote:
>> The performance will be similar, but in the non-degraded case, the
>> raidz3
>> will perform better for small, random reads.
>
> Why is this? The two will have the same amount of data drives....
The simple small, random read model for homogeneous drives:
I = small, random IOPS of one drive
D = number of data disks
P = number of parity disks
total IOPS = I * (D+P)/D
raidz2: P=2
total IOPS = I * (D+2)/D
raidz3: P=3
total IOPS = I * (D+3)/D
-- richard
--
Richard Elling
rich...@nexenta.com +1-760-896-4422
Enterprise class storage for everyone
www.nexenta.com
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