From: "Geo." 

Mirroring is writing the same data to two drives, it's good for data
redundancy where uptime is important because if the main drive fails you
can switch the two drives around and boot from the mirror.

RAID5 is writing data to a series of at least 3 drives, two would be the
actual data and the third would be a checksum of the two. This way if a
drive fails  you can rebuild the data that was on it from the other two. If
you use 5 drives then 4 are data and one checksum, etc.

Raid0 is striping, this is where data is written to 2 or more drives with
no checksum. It increases the speed of reading and writing to disk but lose
one drive and it's all gone.

None of these serves the same purpose as a backup though. With any of these
setups if you delete something by accident, it's gone and you have no way
to get it back. With a backup you would just restore it.

Geo.

"Tony Williams"  wrote in message
news:3DC4E7BB.7020701{at}blarg.net...
> There are a few different RAID configurations; RAID 1 is disk mirroring,
> others deal with striping.
>
> I'm no expert but as I understand it when you mirror two drives they
> both get all the information at the same time.
>
> The OS and system files get stored on both drives and the system will
> read from whichever drive can provde the data - down to the extent of
> reading half a file from one drive and the rest from the other.
>
> Hey, Geo! You know more about this than me - any advice?
>
> --
> Tony
>
> Ellen K. wrote:
> > ?   Aren't mirroring and RAID two different things?   I thought RAID
> > stripes the data on different disks so if one fails the system can
> > figure out what got lost, and mirroring is just what it sounds like...
> >
> > So a mirroring question, does the mirror read from the bad drive or does
> > everything write originally to both?
> >
> > Finally, if the problem is on the part of the C drive that has the O/S
> > and/or program files, what is the result with RAID and with mirroring?
> >
> > On Sat, 02 Nov 2002 21:31:40 -0800, Tony Williams 
> > wrote in message :
> >
> >
> >>Ellen,
> >>
> >>If you're serious about using an extra drive to improve data integrity
> >>you might want to look into RAID mirroring. The various Windows Server
> >>editions support it in software so all you need to buy is the extra
drive.
> >>
> >>Here's a page with a good explanation and links to HOWTOs :
> >>
>
>>http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/WINDO
WS2000/en/server/help/sag_FAULTconcepts_01.htm
> >>
> >>A search for "mirrored volumes" at MS's web site
pulls up several useful
> >>links.
> >
> >
>
>

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