Rép. : Re: Hot Backup

On 8 Oct 2002 at 9:40, Robert Treat wrote:
> Is it me or do doomsdays scenarios sometimes seem a little silly? I'd
> like to ask just where are you storing your "incremental backups" with
> Oracle/m$ sql ?? If it's on the same drive, then when you drive craps
> out you've lost the incremental backups as well.  Are you putting them
> on a different drive (you can do that with the WAL) you'd still have the
> problem that if the building went up in smoke you'd lose that
> incremental backup. Unless you are doing "incremental backups" to a
> computer in another physical location, you still fail all of your
> scenarios.

The complete loss of a building is a small risk, but as I explained, the loss of some/all of the disks is quite usual,
evenwith RAID5.  
(However, fire is a fairly high risk.)

- Redo & Archived logs (oracle) or transaction log (m$ sql) are supposed do be on a different disk than the data.
- Oracle allows storing of archive log files on a remote disk.
- Incremental backups are intended to be performed frequently (hourly, for example) on tapes.
In a secured environment, the tape robot is supposed to be located "far enough" from the server. At least not in the
sameroom. 

In a business critical, production environment, all these security features seem quite standard to me.

IMO, this is one of the big differences between a low level DB manager (Xbase, Axess, ...) and an enterprise level
RDBMS, 
which I think postgres really is on most other points.


By the way: Thanks Shridhar. I'll take a close look your pdf, since it may be the solution of one of our problems for a
newproject. 


Erwan

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Erwan DUROSELLE    //    SEAFRANCE DSI
Responsable Bases de Données  //  Databases Manager
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email: eduroselle@seafrance.fr
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