Question : Backup keeps running out of space??

I have 3 physical drives on my machine, 320gb each. C has XP, E has a bootable copy of XP and is where I store my backup. F has Vista.  I did a full backup of C (219gb) and stored it on e (backup file size is 192gb) So there is 97BGB left on E. I must be misunderstanding how a backup works, because I thought i'd be able to backup a drive with one that is the same size- especially since there is some compression used. Anyway, Whei I tell it to do the incremental, it runs out of space and fills up the 97gb or so of space left available on the backup drive e. I thought it was only supposed to contain new data since the last backup??  I haven't added 90Gb of data since then, I have norton set to keep only 1 base set of the backup, so I can't figure out why it would keep running out of space. I would understand is running out of space if it were trying to duplicate the drive contents again, but it's not ssupposed to be doing that. Any help on this would be appreciated.

Answer : Backup keeps running out of space??

First, thanks for the complete explanation and screenshots.  Very helpful.

>> does one usually need to have double or triple the drive capacity than the amount of data they are backing up??

Yes.  (I'm currently using Ghost 12, but I've used Ghost 9, 10 previously as well as older DriveImage predecessors of Ghost.)  Ghost xx needs to be able to have room for full backup even though you told it to only take an incremental.  

There have been many opinions, whitepapers, discussions, etc. on partitioning strategies.  Many/most of them encourage you to keep your c: operating system partition small (20-50gb) and separate your data from your programs.  Image backups are greate for recovering your XP or Vista pc after hard drive failure, but normal data backups are often easier done with programs such as www.goodsync or syncbackse etc etc.  There are many good data backup programs.

When you update a data backup group or partition, these programs are able to ONLY copy the changed files/folders, and keep them in native (or zipped) format.  Very convenient.

Having an external usb2 hard drive of say 500GB makes it easy to keep multiple copies of your c: partition (10-25gb each compressed).

Also, older video, music files, etc may not need to be backed up as often because many are part of people's collections of vacations etc.

Bottom line:  I would encourage you to rethink your separation of data vs XP in the partitions.  You can use Ghost for both if you want to, and still be automatic as to which partition images are created when.  Also, by keeping the XP partition small, you can even copy your backup-image-file off to dvd's if you choose to limit the chunk size of the images.  I do that and every couple months, burn a few dvd's and store them offsite.