I'm looking at a MegaRAID SAS 9240-4i Sgl card which has a single X4 Mini-SAS SFF8087 connector. As far as I know, such a connector can be expanded to 4 SATA disks. So, I would know how to connect 4 SATA disks. However, the documentation says it supports up to 16 disks in a RAID volume. My question is then; how do I physically connect these 16 disks to the card which only has a single connector?
Is this where backplanes come in (I've tried to find information on that, but can't really figure out how they work together with the RAID controller). ?
Best Answer
Yes, this is where SAS expanders, enclosure backplanes and breakout cables come in. You can obtain a breakout cable that will provide 4 ports from the SFF-8087 mini-SAS connector. You can also try to use something like the HP SAS Expander to provide more SFF-8087 ports for your use from the single RAID controller. A detailed forum about the HP expander is available here.
I mentioned backplanes only because some have embedded expanders that allow them to accommodate more than 4 or 8 drives. You're probably not working with a system with a SAS backplane, so disregard that part and focus on expansion at the RAID card level.