Can only back up once!

[kd4ko]

My intel iMac has a 232.89 GB drive with 69 GB available. I do a normal "file" back up to a Maxtor 200 GB external drive. My initial back up almost fills the drive even though I use compression. I cannot do a second back up because the disk only has 184 KB available. Didn't used to have this problem.

 

David

[twickland]

The amount of compression you can achieve depends on the types of files on your source drive. In addition to the data, your destination drive also has to hold the file backup set catalog, as well as any other files you may have placed there.

 

Your setup is a bit marginal for what you're trying to achieve. You can probably save a little space on your destination drive by keeping the catalog compressed. (Go to Configure> Backup Sets> Configure> Options.) However, this will delay the closing of your backup sessions to some degree, and may also slow some accesses to the backup set. For the small amount of space saved, the tradeoffs may not be worth it to you.

 

A better option in my opinion would be to review what you're backing up and consider what's really needed. Temporary and cache files are rarely important to save, and anything you can easily restore from the original CDs/DVDs, such as applications and perhaps the system itself, are a lower priority. You can exclude these files by using Retrospect's canned selectors or by writing your own selector, and you can test your selector while in edit mode to be sure that it works the way you intend.

 

Perhaps all you really need is to back up your /Users folder and the root /Library folder. This can easily be done by defining them as subvolumes.

 

Finally, external storage is getting pretty cheap. You may just want to spring for a larger external drive. If you need to span multiple external drives, you could select the preference option "Use hard drives as removable disks" and use that type of backup set. Because this option is a kludge, though, I would probably not use it unless I had to. You would also need to store your backup set catalog on a volume, such as your internal drive, that is not one of the backup set's members.