[OpenIndiana-discuss] Garrett D'Amore on using SATA drives in a SAS system

[Sašo Kiselkov]

On 06/26/2012 03:01 PM, Roy Sigurd Karlsbakk wrote:
> Hi all
> 
> Seems Garrett D'Amore from Nexenta has a few things to say about using SATA drives in SAS systems
> 
> http://gdamore.blogspot.no/2010/08/why-sas-sata-is-not-such-great-idea.html
> 
> The digest is "Just don't do it"…

Couldn't agree more. Big-name endors (like Sun/Oracle, Dell, HP, etc.)
need to test each SATA firmware revision they ship for storage products
and often modify it to make it behave more normally. Sun (and other
vendors possibly too) put a small interposer board between the SATA
drive and the SAS expander back-plane in enclosures to make sure this
multi-protocol joyride was going well (most of the time).

In my experience, SATA drives just aren't worth it. Looking at e.g.
Seagate Constellation ES.2 drives in SATA vs SAS varieties, the price
difference is only a few dolars (depending on dealer), so it just isn't
worth the gamble. Plus, SAS is dual-port and multi-path often allows for
better use of the new drive's rather large caches (64MB+) by being able
to satisfy a read from cache while a write is going on.

--
Saso