Too Big Backup Sparseimage File?!

[parabel]

Hello!

I have a 160 GB harddisk in my PowerPC iMac (with OSX 10.4.8) of which only about 25 GBs are used at the moment.
I regularily make backups with SD (version 2.1.3. v80) to a sparseimage file on an external USB2 drive with 320 GB using SmartUpdate (which is great, btw).

Before I updated my backup image today, I checked its size. It was about 57 GB, but that was okay because my internal source disk was filled with some large files at the time I made the last backup.
But since I now removed them from my internal HD, I expected the backup file to get smaller, too.
But instead, it is now about 60 GBs, even though the source disk has only 25 GBs of files on it!

What's wrong and how can I get my backup file to be smaller again?

Thanks for your help! And tell me if you need further information or screenshots or something to help me...

[dnanian]

There's nothing wrong -- there's free space in the image that Apple's sparse image file system hasn't recovered.

You can manually recover the space. Open the Terminal application, then type the following:

hdiutil compact

put a space after "compact". Then, drag the sparse image file into Terminal. Press Return at the end of the line, and it'll shrink the image.

[parabel]

Thanks for the fast answer! Works great

What about an option in SD to let it do this automatically after each SmartUpdate (or every x SmartUpdates)?
For people like me, who like to have as much free space on their external HDD as possible for being prepared to store some other files on it, too.
That would be cool, even if that process can take some time...

[dnanian]

Under consideration, though we keep hoping that, instead, Apple will improve their re-use of free space in the image!

[lars]

Originally Posted by parabel

Thanks for the fast answer! Works great

What about an option in SD to let it do this automatically after each SmartUpdate (or every x SmartUpdates)?

You get my vote as well.
I would love this option.