My DBAs are starting to question me about an RMAN crosscheck they are running.

Essentially I gather that when they ran it the crosscheck seemed to report even backups run in the last 2 days as expired.

On checking the Data Domain unit I can see the images are still there and on running NetBackup commands I see these are NOT expired from NBU’s perspective.

On doing a search I did find a document at Symantec that talked about RMAN expirations but it only went up through 6.0 so I’m not sure if it is still valid for 6.5.  It says essentially that on the NBU side we should set very long retentions (e.g. INFINITY) for all RMAN backup policies then let RMAN keep track of retentions itself.   The downside I see to this is we do vaulting of the images on data domain to tape – we set retention on data domain to 1 month then the vault copies get longer retentions (e.g. 3 months for a daily backup).   How would we get RMAN to set and keep track of such retention differences?

The DBAs have opened a TAR with Oracle to see why the crosscheck is reporting the images as expired but I suspect from the NBU document that the answer will be something like “it is expired so far as RMAN is concerned”.   This also begs the question as to whether RMAN could be used to restore the backups even if they aren’t expired so far as NBU is concerned.  Does anyone know the answer to that?