We use Raid 5.
If we lose a drive, we hot swap it out, no interruption.

If I had all the disk in the world I would do both since mirroring helps.
Here is what the "book" says:

"As the result of a sudden power outage, a partial write occurs. The
recovery log is now corrupt and not completely readable. Without mirroring,
transaction recovery operations cannot complete when the server is
restarted. However, if the recovery log is mirrored and a partial write is
detected, a mirror volume can be used to construct valid images of the
missing pages."

Now, with that said, I have had the power killed accidentally a few times
and had no problem bringing the ADSM server(s) back up.
But I have problems with drives. More than I care to mention! Raid 5 has
saved my butt on more than one occasion.

Like I said, I would love to do both but I don't have that luxury. Worst
case I restore from my most recent Database backup.

Good Luck -
CR

__________________________________________________
Cris Robinson
Sr. Technical Analyst
Enterprise Storage Management / ADSM
Liberty Mutual Insurance
Portsmouth, New Hampshire
603.431.8400.54837
mailto:cris.robinson AT libertymutual DOT com

Dilbert words of Wisdom:
Accept that some days you're the pigeon,
and some days you're the statue!

> -----Original Message-----
> From: Remeta, Mark [SMTP:MRemeta AT SELIGMANDATA DOT COM]
> Sent: Wednesday, April 21, 1999 3:08 PM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      Re: DB mirroring vs. RAID
>
> So if it was on a RAID 5 set and you had lost one disk, your database
> would
> have still been intact and you would have had 0 hours of down time
> (assuming
> the RAID 5 worked the way it was suppose to).
> Sounds like a pretty good case for RAID 5 instead of mirroring.
>
>
>
> > -----Original Message-----
> > From: James, Ron [SMTP:Rjames AT ATSGROUP DOT COM]
> > Sent: Wednesday, April 21, 1999 1:09 PM
> > To:   ADSM-L AT VM.MARIST DOT EDU
> > Subject:      Re: DB mirroring vs. RAID
> >
> > I stand caught - No, Mine is not a Raid set - I had a limited number of
> > drives that I could install so I maximized the total drive space for
> pools
> > and db logs - Certainly if space permits - go for it - I wasn't willing
> to
> > lose 1/n of my drive space for Raid 5. I migrate to tape and a copy pool
> > immediately after completing my backups. It's a personal comfort issue -
> > I'm
> > comfortable with the setup that I have - you may want the additional
> fault
> > tolerance.
> >
> > Ron
> >
> >                 -----Original Message-----
> >                 From:   Remeta, Mark [mailto:MRemeta AT SELIGMANDATA DOT 
> > COM]
> >                 Sent:   Wednesday, April 21, 1999 8:35 AM
> >                 To:     ADSM-L AT VM.MARIST DOT EDU
> >                 Subject:        Re: DB mirroring vs. RAID
> >
> >                 Yes but you did not answer Reinhard's question. Was the
> > 'primary disk' a
> >                 RAID 5 set?
> >
> >
> >                 > -----Original Message-----
> >                 > From: James, Ron [SMTP:Rjames AT ATSGROUP DOT COM]
> >                 > Sent: Wednesday, April 21, 1999 10:00 AM
> >                 > To:   ADSM-L AT VM.MARIST DOT EDU
> >                 > Subject:      Re: DB mirroring vs. RAID
> >                 >
> >                 > Mirroring saved my butt once - I lost the primary disk
> -
> > I
> > replaced the
> >                 > disk
> >                 > and with the help of Kelly Lipp at SSSI we restored
> the
> > server from the
> >                 > mirrored volume - and was well in under a few hours.
> >                 >
> >                 > Ron James
> >                 > Network Management Specialist
> >                 > Premiere Conferencing
> >                 >
> >                 >                 -----Original Message-----
> >                 >                 From:   Reinhard Mersch
> > [mailto:mersch AT UNI-MUENSTER DOT DE]
> >                 >                 Sent:   Wednesday, April 21, 1999 5:44
> > AM
> >                 >                 To:     ADSM-L AT VM.MARIST DOT EDU
> >                 >                 Subject:        DB mirroring vs. RAID
> >                 >
> >                 >                 Hi,
> >                 >
> >                 >                 again I am struggling with my ever
> > growing
> > ADSM DB, not
> >                 > knowing where to
> >                 >                 get the additional disk space I need.
> An
> > option would be,
> >                 > to
> >                 > give up DB
> >                 >                 mirroring and rely on RAID5 instead.
> >                 >
> >                 >                 Since RAID5 protects against
> > media/hardware failures, are
> >                 > there other
> >                 >                 threats, DB mirroring protects against
> > and
> > RAID5 does not?
> >                 > There has been
> >                 >                 discussion on this in August 98 and
> Andy
> > Raibeck mentioned
> >                 > partial page
> >                 >                 writes. But how probable are they? Has
> > anybody out there
> >                 > ever been in a
> >                 >                 situation where DB mirroring (would
> > have)
> > helped and RAID5
> >                 > (would have)
> >                 >                 not?
> >                 >
> >                 >                 Regards
> >                 >
> >                 >                 --
> >                 >                 Reinhard Mersch
> > Westfaelische
> >                 > Wilhelms-Universitaet
> >                 >                 Zentrum fuer Informationsverarbeitung
> -
> > ehemals
> >                 > Universitaetsrechenzentrum
> >                 >                 Roentgenstrasse 9-13, D-48149
> Muenster,
> > Germany      Tel:
> >                 > +49(251)83-31583
> >                 >                 E-Mail: mersch AT uni-muenster DOT de
> > Fax:
> >                 > +49(251)83-31653