Re: HDD vs. RAID (was Re: Lilo Q)

[Brian Dessent <brian@dessent.net>]

"Ian D. Stewart" wrote:
 
> As the size of IDE hard drives increase, what are the
> advantages/disadvantages of using a single large hard drive as opposed
> to a RAID stack (say, 80 GB hard drive vs. raid tower w/ 4 20 GB hard
> drives) ?

I'd say it all depends on the specs of hard drives.  If you're comparing
apples to apples (i.e. the same or very similar models) then the RAID
solution should always be faster.  When you start comparing older to
newer, I'm sure this clouds the situation.

Also realize that with IDE, only one device on an interface can talk at
once.  So if you are doing RAID with IDE drives, you really have to have
each drive on its own interface in order to see a speedup.  So this does
affect the price equation a bit.  If you're running out of controllers,
you could put a CDROM as the slave to a HD master.  As long as the CDROM
supports DMA mode, it will not slow down the HD at all.  You can mix DMA
modes on an interface, but you cannot mix PIO and DMA.  So if you put an
older CDROM that only supports PIO as a slave to an UltraDMA HD, the HD
will not be able to use DMA mode.  And of course, expect a slowdown if
you try to use the CDROM and HD at the same time.

Brian


-- 
To UNSUBSCRIBE, email to debian-user-request@lists.debian.org 
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org