Could someone please help?

[mmorse]

Could someone please tell me why Retrospect 4.3 requires a backup set twice as big as the volume it is copying? I have a firewire drive that contains two backup sets. One for each of my internal hard drives. Every night, retrospect backs up the two drives to the firewire drive. After a few weeks, one backup set grows to twice the size of the amount of data it is backing up. For instance, the drive has 11 gigs of data to backup yet the backup set is over 18 gigs. Incremental daily backups grow at a pace that is not justified by the small amoint of new files created each day. This results in me having to trash the backup set every couple of months and to start from scratch to get the backup set back down in size. The other backup set seems to function as intended. The drive in question is my boot drive.

 

If I can't get this solved, I'm afraid I'll have to dump retrospect for some other backup solution. Any incite is greatly appreciated.

 

thanks

mark

[mcswgn]

It does seem a bit excesive to have a backup set grow that large, but it really depends on the specifics of your situation. Without knowing more I can only hypothesize that Retrospect feels files are changing more on your boot volume than on the other volume. To some extent this is to be expected. There are a lot of system file that change on the boot volume. For example every time a log has a single line appended the entire log will be backed up again. When logs are rotated (typically once a week, although I haven't checked what it is in Mac OS X) all the old logs get renamed:

...

syslog.2 -> syslog.3

syslog.1 -> syslog.2

syslog -> syslog.1

and a new syslog is created

 

None of the old logs are changing, but because their names are different, they will all be backed up again. This is the way it is supposed to work. There is a lot more of this sort of thing happening on the boot volume.

 

If you want to find out what is actually being written to your backup set, go to Reports -> Contents. Select a backup set, then a snapshot, and click Browse. You will see the list of files written in that backup session. If you select a folder in this window you will see its size in the upper right corner. Nosing around here might lead you to where all the volume is coming from.

 

Once you figure out why so much is being written, you may be able to add some filters to eliminate files you feel you don't need to backup. (E.g. browser caches, maybe /var/log, etc.)