The more I look at this issue, the less I think it is really something to do with K3B. But I'm posting here anyway because hopefully the kind, knowledgeable people reading this will have a better clue about what's going on than I do.

I have a DVD I've been using to keep incremental backups with multiple sessions, and I've just noticed that all the files on it are zero length except for the ones that were added in the previous session. (And those files happen to be useless to me, but that's an unrelated story.)

Here's what I *think* happened. I do recall last time K3B warned me that because the incremental backup image (I'm using dar) was quite large this time - over 2GB - something wouldn't work. Joliet? ISO9660? I can't remember exactly. So it had to use UDF. Whatever it was I thought "Okay, that's fine" and went ahead.

Looking at the output of mount, the disc is mounted as UDF, whereas other similar discs without this problem (files form all sessions appear and are nonzero length) are mounted as iso9660. (Using Debian Squeeze, FWIW.)

I can mount this disc manually with the session= option and iso9660 fstype and obtain the files. That option fails for udf fstype, though. Strange... Even stranger, I can manually mount the last session as iso9660, and *all* the files on the disc appear in full!

Anyone know what might be going on? I'm curious (a) just for interest's sake, and (b) in case this might be something that the K3B ought to warn the user about.