Re: rman archivelog delete - Dataguard

  • From: Steve Perry <sperry@xxxxxxxxxxx>
  • To: dd.yakkali@xxxxxxxxx
  • Date: Wed, 1 Nov 2006 17:53:32 -0600

you probably already got your answer, but I'll add my 2 cents.

if you run backup archivelog all... delete input;
rman won't delete the archive logs that haven't been applied to the standby. you should receive the following error:
RMAN-08137: WARNING: archive log not deleted as it is still needed

if you have a run block and have a separate delete statement
i.e. delete archive until time...;
it will delete them even if they haven't been applied.

we want to keep 24 hours of arch logs on disk and came up with the following ideas with pros and cons.
they are just thoughts now, but I'm open to suggestions.

1.) use this run block or something similar
run {
  BACKUP ARCHIVELOG ALL not backed up 1 times;  #or 2 times.
  DELETE ARCHIVELOG ALL COMPLETED BEFORE 'TRUNC(SYSDATE-1)';
}

pros: kind of does what we want. if the backup fails the delete command won't be executed. if it's a separate command, it will execute regardless of the previous command. cons: if the standby is down for more than 24 hours, the logs will be deleted and have to be restored from tape to sync it up.

2.) use
backup archivelog all until time "trunc(systdate-1)" not backed up 1 times delete input;

pros: only backups the logs once and deletes them. won't delete them if the standby crashes. you get the error above. cons: this will always have 24 hours of logs on the disk that have not been backed up.

3.) backup the standby database instead of the primary.
pros: doesn't impact production, doesn't have to worry about the delete problem because they would have to be applied to the standby first. cons: diligent about monitoring the standby to keep it in sync. if the standby is in a remote site, getting the logs to the primary might be an issue.





On Oct 27, 2006, at 10:42 PM, dd yakkali wrote:

Hello RMAN gurus,

I have 2 questions regarding deleting archivelogs in a dataguard environment. I use RMAN to backup my archivelogs to SBT.

physical standby, 10.1.0.3 on solaris 9

1) Using RMAN, how do we make sure archive log is applied on the standby before deleting it on primary. I know i can write a script outside of RMAN to check v$archived_log and look for applied column before deleting.

2) Can we combine multiple conditions while deleting archivelogs using RMAN.

Eg:

delete noprompt archivelog all completed before 'sysdate-2' backed up 2 times to device type SBT;

In the above command I am combining 2 conditions a) completed before sysdate-2 b) backed up 2 times to device type SBT ( I do not know whether it is legal to do so or not )
above command does run without syntax errors, but does not do its job.

Can anybody give me some way of accomplishing these.



Thanks in advance
Deen

Other related posts: