Re: Disk MTBF

copying oracle datafiles as part of a hot backup is not generally referred to as "mirroring" disks. or are you referring to a scheme in which you use triple mirrors, and split off one of the mirrors as part of the backup procedure ?

"Bob Schmitz" <bschmitz_at_execpc.com> wrote in message news:XgQn6.3715$7e6.1468683_at_homer.alpha.net...
> I have found that using mirrored disks to be a good solution for short
 term
> storage for the Oracle backup's. I usually use disks for my nightly
 backups
> because they are the fastest way to get backups completed. After the
 Oracle
> backups are completed our system administrator backs up the Oracle files
> plus other Unix files to tape. With this scenario one is protected ether
> way and is able to get back on-line much quicker. Also, if one has to
> recover, I don't have to want around for the tape to pull it back to disk
> ... a very slow process!
>
> Hope this helps.
>
> -rws
>
> "Fred A G" <nospam_at_allowed.localhost> wrote in message
> news:5hBn6.5593$hi2.16367_at_nntpserver.swip.net...
> >
> > "Roger Menhennett" <r.menhennett_at_lmco.com> wrote in message
> > news:3A9BE9CD.B783FE73_at_lmco.com...
> > > Am wondering what the probability of disk failure is in the following
> > > scenarios for the first year, second year, etc. (assume one machine
 with
> > > a
> > > disk mtbf of 50000hr.).
> > >
> > > 1. One disk.
> > > 2. Six disks.
> > > 3. Six disks configured as raid1.
> >
> >
> > > Am concerned with how much quantifiable confidence one can put in a
> > > raid device to substitute it for backups. Besides device failure,
> >
> > None, nada, nil! A raid device is not a substitute for backup (where you
> > make a good copy of important data to tapes and place the tapes in the
> > media safe(s))!
> >
> > Mirroring/redundacy in raid is for "protection" against disk failure,
> > nothing more. A six disk simple mirroring raid-1 (3 <-> 3) can stand
> > loosing one to three disks. Make sure you spread disks across several
> > HBAs too, just in case...
> >
> > Regards
> > /Fad
> >
> >
>
>
>
Received on Fri Mar 02 2001 - 22:09:43 CST