How exactly does RMan determine what backup files it needs when performing a recovery, and how can I determine? Is there a log or control file that I can browse to find out?
The reason I ask is that I want to put our firm's backups onto tape, but would like to know in advance which tapes will be needed for a particular recovery - for example, if I want to recover from a date last month then I would expect to need more backup files than recovering from last week.
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Still with the same firm (and still trying to sort out the mess!) - RMan's backup job fails every night as it looking for an archivelog that was deleted. The archivelog is not backed up anywhere, so I have tried to recreate it by copying another empty (i.e. 1Kb) log file, renaming it, and changing the seq# in the header - I haven't changed the SCN's in the header as I don't know what they should be. The backup job is still failing, with the error "RA-19563 Header validation failed for file". Any ideas, anyone? (I have also tried running the 'crosscheck archivelog all' command', as RMan suggested, but to no avail).
Are you using a recovery catalog? If so, try a RESYNC CATALOG followed by the CROSSCHECK ARCHIVELOG ALL command. Make sure you are connected to the catalog within rman (connect catalog rman/password@SID where SID is the instance with the recovery catalog).
thanks for the advice, but by asking "Are you using a recovery catalog?" Fate could have answered for me! Unfortunately we are not using a recovery catalogue (cannot connect to recovery catalog after NOCATALOG has been used); is there another way to resolve this?
Seems like the problem is that the archive log has been deleted but that information still exists in the controlfile. I'm guessing your backup job is based on this controlfile and thus, won't work unless you have that archivelog. It's going to be difficult to fool Oracle into thinking it is there just by placing a renamed file in that location. The only way I can see to get a good fix to the problem is to rebuild the control file and then immediately take a backup. You should be able to find procedures for this in the doc. Controlfile rebuilds can be a little risky and tricky, so plan it carefully - good luck!