On Fri, Feb 27, 2015 at 1:53 PM, Robert Arkiletian <robark at gmail.com> wrote: > Still have good quality older sata hardware raid cards that require 512 > bytes/sector. As far as I know HD manufacturers are not making native 512 > bytes/sector drives any more. 512n drives still exist, although they tend to be a bit smaller, 2TB or less. http://www.hgst.com/tech/techlib.nsf/techdocs/FD3F376DC2ECCE68882579D40082C393/$file/US7K4000_ds.pdf 4Kn drives are appearing now also. I don't expect these drives to be bootable except possibly by systems with UEFI firmware. It's also possible hardware RAID will reject them unless explicitly supported. http://www.hgst.com/tech/techlib.nsf/techdocs/29C9312E3B7D10CE88257D41000D8D16/$file/Ultrastar-7K6000-DS.pdf > Some have better 512e emulation than others. Looking for some advice on > which to avoid and which are recommended. Thanks. PS this is for a CentOS6 > server. The emulation implementations don't come into play if the alignment is correct from the start. The better implementations have significantly less pathological behavior if alignment is wrong, but that's anecdotal, I don't have any empirical data available. But I'd say in any case you want it properly aligned. -- Chris Murphy