as there are good samples of a recovery for ML1 and ML2 datasets when the running DFHSM CDS don't have the information any longer, means we have to use the backup CDS here - it raises the question what is needed when there are only backup records (basically B/C) left to go on? What fields are really needed to make a successful restore besides restoring the complete records of both.
If we are talking of GDS we only have one B and only one C record. Anything else makes things more complicated.
So let's see if anyone knows for the easy way.
A lot will also depend on your TMS (if installed) and VTS settings (if installed) for ML2 resident datasets.
Example from when I was working in Munich - I managed to restore the CDS back to a new name, and completely set up a new version of HSM on the test system using the restored CDS. The ML2 tapes had expired and were immediately scratched from the VTS catalog but were retained for 3 days on the TMS.
So basically another thing to look out for would be that the VTS cannot immediately set to scratch any tapes released. The VTS and TMS need to be kept in sync.
Thanks for your feedback, very welcome. A thing of course is to have the tapes still available. Basically that is given as much of the data do not expire at the same time (means backup tapes are still valid) and then there is a period in IBMs VTL that says do not overwrite data unless you have to. So chances are high that one can recover with an older set of the CDS restored from CDSVERSIONBACKUP.