Creating A Differential Backup
I am currently using a full backup that runs Mon - Fri. The amount of data is starting to exceed the original amount of tapes I had set aside, so I have decided to create a differential backup. I would run the differential on Monday - Thursday and I would run the full backup on Friday. I would like to keep the data for 90 days (this is set in stone by the powers that be), the same as my full backup. I estimated that I could use no more than seven tapes, four differentials and one full, with two for scratches. I have a few questions.
1. Would BE let me use the incremental tapes over until they are full? I assume yes since I have multiple full backups on any given tape now.
2. I set the OPP for 90 days and the APP for Infinite - Allow Append. Would this be the correct settings (BE defaulted to this when I choose my 90 days)?
3. Would seven tapes be sufficient? The amount of data that actually changes daily is less than 15 gigabytes. I would rotate four of the daily tapes (Mon - Thurs) for the differential. With the full backup on Friday, I would have three tapes to use, two for the normal rotation and one for a scratch.
I have never done a differential backup scenario, so any help would be greatly appreciated.