A kinder, gentler Recycle backup

[Flyby]

Hi:

 

I was Retro to backup my Raid 0 drives to a dedicated internal drive. As it began to fill I ran a Recycle on one of the volumes to save space. The Recycle erases the previous backup before creating the new backup. I understand this for tapes, etc. but in my situation I would prefer the opposite, create then erase.

 

Is there an easy way to do this without transferring backup sets or rewriting scripts?

 

Thanks;

[RonaldL]

If you have the disk space, you can create two backup sets and alternate recycling between the two. If you have Retrospect 7.0 or newer, you may want to look into the grooming option for disk backup sets.

[Flyby]

Thanks for your reply.

 

I use a 232G dedicated drive but it hits the halfway point fairly quickly so doubling-up might be tough. I looked at grooming but I'm not sure how that fits in with Progressive backups. If I understand it correctly Progressive just builds on a base backup so what does it delete, if all the files are necessary to reconstruct a volume?

 

I can do it the way I originally planned, recycling when things got bloated, it just seems more sensible to create the new backup before wiping out the old, just in case.

 

My backup gets backed-up so I may be a little ******* on this one, I just wanted to be sure I wasn't missing something on Recycles.

[RonaldL]

Yeah, recycles delete the files previously backed up before backing up the data again.

 

Here's a brief overview of how grooming works: http://kb.dantz.com/article.asp?article=8146&p=2 Basically, when old snapshots are groomed out, Retrospect figures out what files were in those snapshots that are no longer in other snapshots and it deletes them from the backup set. Also, if a file changes before every backup, the version of the file from the snapshot will be groomed out, leaving the more recent versions of the file in the backup set.

[Flyby]

Does this make sense.

 

I ran a recycle on my external doomsday drive because it was down to 4g free. I ran the recycle on a smaller volume, and when I was done I had 2.4G less free space than when I started. So the recycled backup actually took more space than two months worth of Progressives.

 

If I do the same on the larger volume (100G) I will run out of space for sure during the backup. Compression level didn't change (none). I thought the idea was to save space.

[Flyby]

Follow up post.

 

I just tried it again on a different volume on a different drive, with these results;

 

Before the recycle backup the drive had 62.6G free. The backup set was 1.88G which was for base and incrementals for 1.12G of data.

 

After the recycle backup the drive had 61.6G (1.0G less space), and the backup set had 1.01G (0.87G less). So while the drive should have increased by .87, it went down by 1.0 for a net loss of 1.87G. It seems like the data that was supposed to be erased during the recycle was moved, but I haven't found it yet (haven't looked too hard)

 

It may be a coincidence but that same proportion held on the first test on the other drive, the drive lost an amount equal to the original amount of data.

 

Has anyone experienced this?