Scheduling a combo weekly-monthly rotating backup

[jbezdek]

Hi there. I'm a recent convert from Retrospect and I'm a big fan. Nice piece of software.

I'd like some suggestions on how to most closely duplicate the scheduled backup plan I implemented in Retrospect. I have three backup drives--Andy, Barney, and Opie--that are backed up daily on a rotating weekly schedule. So each drive is backed up every day every three weeks. (Make sense?) This is easy for me because I know I just need to swap out the drive each Saturday night.

Due to the way SD! schedules backups (1st-4th week of the month), it's difficult (impossible?) to duplicate my "every 3 weeks" backup strategy without advanced scripting, etc. I'm therefore considering moving to a plan where two drives are used for weekly backups and the third for monthly backups.

But before I do that, I want to ask: is there a way to schedule a rotating backup plan with an odd number of backup drives? I can't figure out how to scheduled two rotating backup drives while still maintaining a significant time lapse between the backups on each drive. What I mean is: if I only have two drives that rotate (say, every other week), and each does a daily backup, there will be a day where the timestamp of the two drives will differ by only 1 day (e.g., one runs on a Saturday, the next runs on a Sunday). And in fact, the greatest difference in time stamps would only be 3-4 days. This doesn't seem like enough protection to me against unintended deletions, etc. (And even if I moved to a schedule where the backups rotated every 2 weeks, there still would be a day when the two backups would differ by only a day.)

Given SD!'s current scheduled backup abilities, my only option seems to be to jump all the way to four rotating drives. This would allow me to swap a new drive in every week and still ensure that there exists at least a week difference between every backup.

Am I missing something? Is there a way to make this work?

Thanks.
Joe