Nathan Straz schrieb:
>
> On Tue, Nov 13, 2001 at 09:13:11AM -0700, D. Stimits wrote:
> > FYI, I've managed to get just over 30 MB/sec sustained (read; write
> > isn't too far off; both XFS and ext2 do well with average size files) on
> > a good 10K rpm U160 scsi drive (64 bit 66 MHz bus) if conditions are
> > right...no raid at all. With 5 drives on RAID 0 and your hardware specs,
> > can't imagine not getting far better than you get now. It sure sounds
> > like something is wrong.
>
> Why? IIRC, RAID0 is just concatenated disks. You're not going to get a
> speed boost out of it. Not until RAID1 (mirrored) will you start seeing
> a speed boost.
RAID0 greatly boosts performance because data is spread on several
disks, what you mean is a linear array where you concatanate disks.
RAID1 boosts read performance because it optimizes reads to read from
both drives. Write performance is almost identical to a single drive.
With RAID5 it's not so easy to say but generally it also boosts
perfomance well.
BTW I'm only talking about Linux SoftRAID here.
-Simon
>
> --
> Nate Straz nstraz@xxxxxxx
> sgi, inc http://www.sgi.com/
> Linux Test Project http://ltp.sf.net/
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