Request for opinions - gvinum or ccd?
wojtek at wojtek.tensor.gdynia.pl
Sun Jun 7 07:01:42 UTC 2009
>> (very roughly, in the non-sequential access case) expected to deliver
>> performance of four drives in a RAID0 array?
> According to all the Sun documentation, the I/O throughput of a raidz
> configuration is equal to that of a single drive.
exactly what i say. it's like RAID3. Not RAID5 which have close to n times
single drive throughput on read and rougly n/4 on writes.
> We remade the pool using 3x 8-drive raidz2 vdevs, and performance has
> been great (400 MBytes/s write, almost 3 GBytes/s sequential read, 800
why write performance is so slow? in Sun theory it should have the same
speed as reads. I would say that it should be even better a bit -
filesystem get data first in cache and can plan ahead.
> MBytes/s random read).
random read on how big chunks?
Are you sure you get 3GB/s on read? it would mean each drive must be able
to do 140MB/s
What disks do you use?
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