So you really can push a SATA2 disk into a SAS backplane?

Solution 1:

It works. SATA discs are compatible with SAS. I have tons of them in SAS backplanes. Work like a charm.

Solution 2:

Yes, difference: SATA devices contain a gap between the power and the data connectors, while the SAS devices do not. Meaning: You can connect a SATA device to an enclosure that supports SAS and SATA, but (hopefully;) not the way around.

Solution 3:

You should install an interposer board between HDD and the backplane in case you have problems. See: