I recently bought some cheap “NetApp X417A-R6” SAS drives on Ebay - NetApp X417A-R6 900GB 2.5" SAS ST900MM0036, specifically. Come on, a 900GB 10k RPM SAS drive for $12.50 seemed like a good deal to me. Intro The problem, it turns out, is that these NetApp drives have 520-byte sectors, while my R610’s PERC 6/i RAID controller apparently only takes “standard” sector sizes such as the more common 512-byte.