On Sat, Feb 28, 2015 at 12:33 AM, Robert Arkiletian <robark at gmail.com> wrote: > According to this pdf [1] alignment is important but from what I understand > 512e emulation still has a small RMW performance hit from writes that are > smaller than 4k or if the writes are not a multiple of 4k. There shouldn't be writes smaller than 4KB since ext234, XFS, and Btrfs all use 4KB block sizes. There is a possible case where the XFS journal writes are 512 bytes, this can be fixed by specifying a 4KB sector size at mkfs time if it's not auto-detected. > Also it's probably not a good idea to mix 512e with 512n in a raid set. Scrambled eggs mixed with yogurt? Offhand it doesn't seem like a bad idea (won't kill me), even if it also may not be a good idea (sounds suboptimal). -- Chris Murphy