[CentOS] HA Storage Cookbook?

Fri Nov 7 22:46:36 UTC 2008
Joshua Baker-LePain <jlb17 at duke.edu>

On Fri, 7 Nov 2008 at 2:35pm, nate wrote

> Gordon McLellan wrote:
>
>> I guess I'm saying, if you interpret the name "Serial Attached Scsi"
>> literally, then the Seagate ES.2 is not an SAS drive - it is not a
>> scsi drive with a serial interface.  However, if you interpret SAS as
>> an interface standard, then the interface board determines what the
>> drive is, more so than its mechanical construction.
>
> SAS and SATA use the same physical interface, the drive mentioned
> is most definitely SATA. Largest SAS drive I have heard of
> myself is 400GB, same as the max size for FC drives.

No.  No it isn't.  It's SAS.  The platters etc are the same hardware used 
in the SATA part, but the interface circuitry is native SAS.  Note that 
they offer the drive in both SATA and SAS variants.

While SATA and SAS are *supposed* to be able to be mixed freely, my vendor 
has warned me that it doesn't always work out that well.  They have seen 
compatibility issues using SATA drives on SAS controllers.  So for 
applications where you want/need a SAS controller but still need big 
capacity, these are the drives they recommend.

-- 
Joshua Baker-LePain
QB3 Shared Cluster Sysadmin
UCSF