A couple of years ago, I was managing 2 systems. Both were built with
Supermicro motherboards and chassis and high-end 3ware controllers
(9550sx if I recall correctly). One system was built with
enterprise-class SATA  drives, while the other was built with
desktop-class SATA drives. They were both configured for RAID5.

The system with desktop-class drives occasionally kicked a drive out
of the array. The controller would report that the drive had failed
and then that it was back again a few seconds later, but this was
enough for the controller to kick it out of the array and require a
rebuild.

Caution: one anecdote is not hard data!

Simon

On Wed, Mar 17, 2010 at 7:36 AM, Matt Garman [off-list ref] wrote:

Hello,

For building a Linux md system with many disks, I've been looking at
the LSI SAS 3081E-R controller card[1] with the SuperMicro
846TQ-R900B chassis[2].  The SAS3018E card looks like it has a
mature open-source Linux driver.  The chassis has a SAS expander;
I'm not sure which one (but I have a question in to SuperMicro).

Anyway, my question is this: has anyone used this setup, or one
like it (sas controller + sas expander) with "desktop" class drives?
The web research I've done suggests that most SAS controllers and
expanders are targeted at the enterprise market, and therefore,
aren't guaranteed to work with the (significantly cheaper) desktop
drives.

For example, from the FAQ for that SuperMicro chassis[3]:

   Question: We want to use the new Seagate 1.5TB ST31500341AS
   drives in combination with a storage solution based on your
   846TQ chassis, is this compatible?

   Answer: This ST31500341AS hard drive is designed to be a Desktop
   type hard drive, not an Enterprise hard drive which is needed in
   this setup.  We don't recommend this combination, so please use
   the Seagate 1TB ST31000340NS drive instead. This drive is an
   Enterprise drive and validated for our 846TQ chassis.

In short, we want to build a server with 24 drives.  The desktop
drives are significantly cheaper than the enterprise drives.  But
getting 24 ports is cheapest with these SAS controllers + expanders.

Thanks,
Matt


[1] http://www.lsi.com/storage_home/products_home/host_bus_adapters/sas_hbas/lsisas3081er/index.html

[2] http://www.supermicro.com/products/chassis/4U/846/SC846TQ-R900.cfm

[3] http://www.supermicro.com/support/faqs/faq.cfm?faq=8230

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