Yes Axr2., I did see the metalink post. The reason I ignored it was that it states that this problem will occour only when you use the controlfile to backup. In my case I'm using the catalog. The backup piece deletion option does not work, because there is no backuppiece in the disk. So it would require you to run the crosscheck and then do delete expired backup. Which I tried and was not successful. At this juncture I have opened a Tar with oracle and lets see what they have to offer.
It is true that when your brains are fried, you cannot think clearly in depth. Here is the solution, for my problem.
1. Since I was lucky, I was able to retrive the disk backups from our usual daily backups on tape. For my luck, we backup the disk backup directory to tape.
2. Issued the following commands on those disk backup sets with the status unavailable on RMAN.
change backupset available;
3. On the OS moved the files to another directory
4. Ran the cross check, this expired the backups
crosscheck backup of archivelog all;
5. Deleted the expired backups from catalog
delete expired backups;
6. Reran the validation. Bingo, its all working.
The validation completed successfully.
So, the solution in short is that when you have the backupset marked unavailable, RMAN seem to include those sets also in its validation process, and ademantly looks for those backups for the validation.
I concern is that its going to be an issue when you go for a longterm backup policy, where you take a full backup once a month and hold them on for a long time. The way Oracle suggest that you can achieve this on 8i is by marking those backupsets unavailable. In this can, it wouldn't work well looks like at this juncture.
I'm yet to hear from Oracle, why this is happening?
I concern is that its going to be an issue when you go for a longterm backup policy, where you take a full backup once a month and hold them on for a long time. The way Oracle suggest that you can achieve this on 8i is by marking those backupsets unavailable.
Where does Oracle suggest this? Is this actually documented somewhere?
This is completely bizzare that you had to restore the bs to mark it expired. I'm soon gonna be backing up an 8i target with 9i catalog with retentions of 7 years. Guess some serious testing needs to be done.
Thanks for the followup. Do post again with Oracle support's official response.
Here is a the extract from chapter 3 on RMAN user guide:
The unavailable option provides for cases when a backup or copy cannot be found or has migrated offsite. A file that is marked UNAVAILABLE is not used in a restore or recover command. If the file is later found or returns to the main site, then you can mark it available again by using the available operand. Note that you do not need to allocate a channel of type maintenance for this operation.
Note: You must use a recovery catalog when executing change ... unavailable and change ... available.