Recommended Number of Back-ups Before Recycle

[Paul Ripley]

I've searched the manual and this forum, but I couldn't locate the answer.

 

Is there a recommended maximum number of back-ups to a media set before recycling the set?

[twickland]

This is largely an issue for each user to decide, depending on the type of media set, number of files on each source, frequency of backups, and how often the files are modified. 

 

The advantage to recycling less often is that, assuming you're performing normal incremental backups, your backups will take less time after the initial backup and will use less media for each backup. The disadvantage is that a large restore operation is likely to take more time if a large number of media set members need to be swapped in to complete the restore. This could be especially annoying with a tape backup set that has more members than the capacity of one's tape library.

 

Whatever frequency you decide on for recycling, be sure to have at least two media sets you rotate between so that you still have adequate backups available when you recycle one media set. Even better: since media is now so cheap, consider performing a new media backup instead of a recycle backup whenever your media set gets to be as large as you care to manage. With a new media backup, you have the advantage of easily switching to fresh media, while enabling you to retain and store the old media set in case you ever need to access the backed up files in the future. 

[Lennart_T]

If you use disk media sets, I recommend grooming instead of recycling. That way you always keep some backups. With recycling you lose them all.

[Daniels]

Depends on how many members each media set has and how often you want to start over with a fresh backup.  It also depends on how many media sets you have and how often they get used.  When I was using tape backups I had two groups of five sets that were rotated weekly which came out to recycling a specific media set every 10 weeks.  Since each set had up to four members I was able to go ten weeks before recycling.

[Paul Ripley]

Thanks for the suggestions.

 

I'm backing up my desktop computer to a single external disk partition.  Just one media set.  Maybe I'll try grooming.  Adding a second external disk would certainly help.

 

I don't remember where I read this, but I was under the impression that the Retrospect database (snapshots, etc.) got very complex after 10 back-ups, and was prone to problems.  I guess that is not true.