Not all SATA is alike - especially if it’s SAS
Posted in Storage Interconnects & RAID, Advisor - Tom by Tom TreadwayI recently read a good column from Arun Taneja at SearchStorage.com that explored the benefits of using SATA drives as primary storage in the data center. He mostly discussed buying criteria for selecting the right SATA products, but he also touched on how SATA could be used in a SAS environment . IMHO, that’s one of the greatest benefits of SAS - the ability to intermix SAS and SATA in a highly reliable, highly expandable topology - and still get incredible performance results. So I’d add one more requirement to the selection criteria for a SATA system - make sure it’s a SAS system that supports SATA drives. This includes selecting SAS HBAs, SAS RAID controllers, and SAS enclosures. It they’re SATA only, you’re painting yourself into a corner.
TT
October 14th, 2005 at 8:44 am
Intermixing of SAS and SATA in the same chassis you say? I say yes, but not in the same RAID set. If simply just for the differences in reliability alone. Other reasons: capacity, and performance as well.
Better to segregate your RAID sets between SAS and SATA especially if your SAS is supporting primary applications and your SATA secondary applications. It is a logical separation from my perspective…
SR
October 14th, 2005 at 9:02 am
I agree 100%. The performance and reliability characteristics would simply be bizarre. The GUI should warn the user if they accidently mix drive types within an array. But the one situation where a mix could be allowed is with hot spares after a drive failure. It would probably be better to have a mix of drive types than risk data loss. And the hot spare be “copied back” as soon as the original drive is replaced or repaired.
TT