quick question regarding dar. how exactly does their incremental backup work? i created an archive the other day which was cut into 8 - 700M slices. now yesterday i created an incremental based on the previous backup and it's only a few k big... but when i list the archive, it shows everything that was in the first backup... so how do i determine exactly what was changed in this archive???? does it become like a new index for the complete backup?

Question 1: when you say the listing of the differential backup shows everything that was in the first backup, do you mean?
a) the listing shows the directories only
b) the listing shows the directories and the files in them

Question 2: did you use the -D option in making the backup?

If you used -D, the backup will preserve the directory tree, but will not backup files in the directories flagged by the -D. Listing the differential could make it seem that you backed up the entire system, when actually you have preserved the directory tree, and made differential backup of files for which ctime has changed since the first backup.

The DAR tutorial has more information in the sections relative to differential backups and the catalogue of the backup. Listing the catalogue could answer your question about what was actually stored in the differential backup. If you created the catalogue database, the differentials are added sequentially to previous catalogues. That's how DAR keeps track of the order of backups, so that they can be restored in proper sequence.

For further reading, there is also a Dar differential backup mini-HOWTO (I don't remember where I found it).

1) it shows all directories including files

2) i'm not 100% sure if the -D option was used as i used kdar to create the archive. although i did export it out to a shell script for future reference, so i can take a look and see if it's there.

thanks for the reply.

Hi,

this might be the howto bigrigdriver was talking about:

(see next post!)

Something in there isn't clear to me:

It says you create one full backup (on the 1st of every month).
Then you create differential backups (2nd-31st of every month).

But: each differential backup you start with his script refers to the last backup you made, whether it was the full or a differential backup!

I don't get that. I thought a differential backup always builds up on the last FULL backup and NOT on the last differential backup, as that would then be an incremental backup!

Is that Howto simply wrong, or do I get it wrong?

Are the "differential backups" he mentions actually incremental backups?!

Again, Hi to everybody!

As I'm new here I couldn't post a link in my first posting.

So here it is:

http://gradha.sdf-eu.org/textos/dar-...-howto.en.html