On Tue, Jan 15, 2013 at 07:49:10AM -0500, Phil Turmel wrote: > You are neglecting each drive's need to skip over parity blocks. If the > array's chunk size is small, the drives won't have to seek, just wait > for the platter spin. Larger chunks might need a seek. > Either way, you > won't get better than (single drive rate) * (n-2) where "n" is the > number of drives in your array. (Large sequential reads.) This can't be right. As far as I know the md layer is smarter than that, and includes various anticipatory codepaths specifically to leverage multiple drives in this fashion. Fwiw raid5 does give me the near-expected speed (n * single drive). Cheers -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
