What does the progress bar mean?

Question

I have just started using TM after installing Leopard a few weeks ago. My plan is to continue to use Super Duper to do a weekly, bootable backup, but to use TM for essentially data backup. With that in mind, I have excluded system files, applications, and other partitions on the backup drive, figuring that the actual amount of data to be backed up will be relatively small.
On it initial backup the progress bar showed 30 GB possible and when the progress bar showed 10 GB, which was far more than I had anticipated, I stopped it, thinking that I needed to fine tune what I was excluding. When I look at the file, backups.backupdb, I see that it's right around 2 GB right now.
This leads me to believe that the progress bar on the initial run is only indicating how much of the data has been evaluated not necessarily how much has been backed up. Can someone confirm this or set me straight on just what the progress bar is telling me?
-Bill

Answer 1

One of the things I noticed is that I had indeed left out one of the partitions on the very drive that I am using as the TM backup. I know that TM won't backup its own backup, but I don't think it can identify other partitions on the same drive. The partition in question actually contains the SuperDuper backup, something I don't need on TM. I did go back and exclude it and the calculated backup dropped from 30 GB to 20 GB, which is still way in excess of what I am actually wanting to back up.
Given what you have said about potentially damaging the backup, perhaps I need to start over. How would I go about doing this, just delete the existing backupdb file? Then go in and rework the excluded files and really narrow things down. This does seem, however, to defeat the process somewhat, the idea of just let it do its thing.
Since my photos and music are already kept on an external drive, on the same partition, in fact, that I will be keeping the TM backup, those are files which do not come into the TM picture. Actually the more I think about this the more dicey it is becoming.
What I have been doing up until now is doing a weekly SuperDuper backup and copying my Documents folder separately. I have five folders, representing up to five weeks in a month and would copy the Documents folder into week one the first week of the month and so on throughout the month. Then next month I would overlay week by week what I had done before. That assured me that I would always have one month of Documents should I restore a SuperDuper backup beyond what was in the Documents folder on that particular SD version.
What I am wanting to do is essentially the same thing except use TM to backup the Documents folder. Perhaps that's a too narrowly defined and too difficult to implement use of TM. Perhaps I have to rethink this. Comments?