single disk vs. RAID5 (amr)

[Mikhail Teterin]

[Subject changed]

п'ятниця 09 червень 2006 13:20, Scott Long написав:
> > I never benchmarked the speed on the single drives, other than to compare
> > with my RAID5 array (which puzzlingly always loses to a single drive, but
> > that's a different story).
>
> All depends on access alignment and cache behaviour.

Well, this does not tell me much :-( I compare a single disk vs. a RAID5 array 
of 6 such disks joined using amr(4). I tried to figure out the best 
FS-parameters for the RAID, but whatever I tried, it was always quite 
inferior to the the single drive -- on both reading and writing.

Perhaps, adding the battery-backup option to the RAID card would improve 
things, but I expected it to be faster even without it.

	-mi