On 26/04/10 03:02 PM, Dave Pooser wrote:
I'm building another 24-bay rackmount storage server, and I'm considering
what drives to put in the bays. My chassis is a Supermicro SC846A, so the
backplane supports SAS or SATA; my controllers are LSI3081E, again
supporting SAS or SATA.
Looking at drives, Seagate offers an enterprise (Constellation) 2TB 7200RPM
drive in both SAS and SATA configurations; the SAS model offers one quarter
the buffer (16MB vs 64MB on the SATA model), the same rotational speed, and
costs 10% more than its enterprise SATA twin. (They also offer a Barracuda
XT SATA drive; it's roughly 20% less expensive than the Constellation drive,
but rated at 60% the MTBF of the others and a predicted rate of
nonrecoverable errors an order of magnitude higher.)
Assuming I'm going to be using three 8-drive RAIDz2 configurations, and
further assuming this server will be used for backing up home directories
(lots of small writes/reads), how much benefit will I see from the SAS
interface?
I would expect to see the SAS drives have built-in support
for multipathing, with no extra hardware required.
Also, hear yourself chanting "but SAS is more ENTERPRISEY"
over and over again :-)
I don't know of any other specific difference between "Enterprise
SATA" and "SAS" drives.
James C. McPherson
--
Senior Software Engineer, Solaris
Oracle
http://www.jmcp.homeunix.com/blog
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
