Re: RMAN retention vs. netbackup retention

On Dec 19, 11:48 am, "EscVector" <J..._at_webthere.com> wrote:
> On Dec 18, 3:47 am, "sm" <mike..._at_gmail.com> wrote:
>
>
>
> > We're running RMAN backups of Oracle 9iR2 databases using libobk media
> > management libraries to send data to a Netbackup tape library. The
> > backups from Netbackup's perspective have a specific retention based on
> > what I choose to back it up with:
>
> > 15 days for archived redo logs
> > 2 weeks for a daily backup
> > 6 weeks for a weekly backup
>
> > However, RMAN simply has a single RMAN config switch called RETENTION
> > PERIOD which i can either set to n days or n copies.. We've decided on
> > 90-days (ie. retention period of 90 days), but this doesn't match with
> > what Netbackup's retention policy would say. After all, RMAN's
> > retention period would keep 90 days worth of records of archive log
> > backups, yet only 15 days is available on tape. I may have understood
> > it wrong but that's the problem I see in my environment. If I do a:
>
> > list backup of archivelog all
>
> > .. I'd find 90 days worth of archivelogs. Yet when I do a netbackup
> > poll of the rman archive logs, it'll only have 15 days worth.
>
> > Does anybody else have this issue, or addressed it somehow?There are 2 retention policies of note:
> 1. Recovery Window Backup Retention Policy:
> If you need to recover to a point in time two weeks ago, use
> this.
> Configure retention policy to recovery window of 14 days;
>
> 2. Backup Redundancy Backup Retention Policy:
> This keeps x copies of each backup. If you run full backups for 3
> days and your redundancy is set to 4, the 4th day's backup will
> obsolete the 1st days backup. It will not remove it, just obsolete it.
>
> The issue you have is the coordination between physical netbackup and
> the rman catalog. Is there a mandate that you only retain 15 days
> worth of archive on tape? Do you vault your netbackups?
>
> Either way, the coordination between netbackup and actual catalog can
> be maintained by using the "CHANGE...Unavailable". Trying to
> coordinate each backup type with the retention policy seems like asking
> for some trouble. What if you need those arch logs and you've deleted
> them? Keep is simple, keep all backups for 'x' time.
>
> If you really want to fine grain the backups, you can put the KEEP
> command in the backup script, thus overriding the retention policies.
> Example:
>
> RMAN> backup database keep until time = 'sysdate + 15' logs;
>
> Starting backup at 19-DEC-06
> using channel ORA_DISK_1
> using channel ORA_DISK_2
> backup will be obsolete on date 03-JAN-07
> archived logs required to recover from this backup will expire when
> this backup expires

6 week retention: 42 ....

RMAN> backup database keep until time = 'sysdate + 42' nologs;

Starting backup at 19-DEC-06
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=156 devtype=DISK allocated channel: ORA_DISK_2
channel ORA_DISK_2: sid=155 devtype=DISK backup will be obsolete on date 30-JAN-07 archived logs required to recover from this backup will not be kept channel ORA_DISK_1: starting full datafile backupset Received on Tue Dec 19 2006 - 10:58:33 CST