Re: Backup strategy

In article <3r1ms7$o6s_at_caesar.ultra.net>, droth_at_dr.ultranet.com (David Roth) wrote:

> Cold backups are the easiest to deal with.

I agree, but we don't all have the luxury of cold backups.

>
> Oracle can be told to mirrow redo log files.

That is true, but he was asking about archived redo log files. Only volume shadowing or hardware/software mirroring outside of Oracle will help (I don't THINK there are other options).

BTW, mirroring your online redo log files is REALLY important. Under Version 6, you didn't have the option. If you lost the drive with your online redo log files, you were toast. You had to shut down and restore your entire database (every data file, etc.). You would only be able to recover what was in your archived redo log files. Depending on the size of your online redo log files, and how quickly you filled them, that could be ALOT of data.

Under Version 7, you can mirror the online redo log files (and guys, mirror them onto two DIFFERENT disks, okay? Preferally on different controllers, too.). If you DON'T do this, you will be just as exposed as you were under version 7. Its kinda hard to explain that a single drive failure can set you back 10 hours (the amount of time it would take to call up the tapes from our offsite facility and recover a 6.5 gig database). If you go by the book, you should then shut down and do a cold backup (yet another 8 hours). Hmm. Maybe you should just mirror the damn online redo log files. ;-)
>
> >: Yes, its a pain to run in archive log mode, but if you need your data
> >: (and who doesn't), it is really the best option.
 

> > What is the pain actually? (Our database is still not in
> >archivelog mode now) Performance degradation? Hard Disk space
> >consumption?
>
> If you do cold backups you olny need to keep the log files since the
> last backup.
>

Ah, yes, but what happens if the cold backup tape is bad? It has happened. We had a bad batch of tapes and had to go back SIX backup tapes. Chilling thought, but its better to keep several tapes than keep your resume up to date.

Matt... Received on Tue Jun 06 1995 - 00:00:00 CEST