Catalogue retention policy

As a add-on, tapes usage also be considerable.

Say you are running 2 diff type of catalog backups with 2 set of tapes. one is incremental tape that will be kept in your location and another is weekly full backup that will be send to offsite for DR.

So incremental catalog policy retention can be same as incremental file system backup retenion and weekly catalog policy retention can be same as weekly file system backup retenion.

this is will help you more while DR.

I agree with Bob, frequency is the key here.

What would you do with a year old catalog tape? Restoring your NetBackup catalog to one year ago today would mean a catalog with many references to tapes and images which have already expired in the past -- assuming you had backup images that expired at some point in the last year. In most companies that means the tapes would be placed back into a pool to get used again by another image and the disk images were long deleted.  Restoring the catalog to one week ago versus four hours ago is also a big deal - you'll have to import a weeks worth of tapes to get back up to speed. Not an easy proposition depending on your hardware resources.

Frequent backups with relatively short retentions are the norm for catalog backups.

As others mentioned, frequency is the key here but it also depends on schedule type for catalog backup. If you perform FULL backup for catalog everytime or frequently then you do not need long retention but if you perform FULL catalog backup only once a while and incremental on regular basis in that case you may want to match retention or go one level up.

For all the above, are we referring to cold or hot catalog backup?

From my understanding, hot catalog will write some disaster recovery files to a particular location. And we will require both the catalog and the DR files during the recovery.

In 5.x we did the cold catalog.
in 6.x we do the Hot Catalog
I back up the catalog every day, and when I sent that days tapes off site a catalog tape was always included.  This is because if we had issues I know I could get the last days tapes and the current catalog would be with it.
Now some tapes are sent off site for 6 months.  So the catalog tape that goes with them quickly becomes outdated.  But I would rather have it off site the next day then to hope I know where my current one is.
When the offsite container comes back we just reuse it.

Now on 6.x with the hot catalog, we still send the catalog tape off with each days backups so we have the most current catalog offsite.

As for the DR file.  I don't know what everybody else does but I...

1) have it set up to email me the file .. so I have it on my BB if I need it (just a text file with info).

2) I have setup a parent_end_notify on my master servers (2).  When the Hot catalog backup finishes the parent_end_notify script runs and does an rdist of the directory with the DR file in it to my master at my DR site (to a differnt dir so the two don't get mixed) ,  The DR master does the same and rdist's his file to my prod master.  So again I have the most current DR file on each of the masters to with the catalog tape in my offsite storage container save to my other location.  I have a cron setup to remove any file over 6 months old. (Don't think I will ever need one that old but just in case).