Backing up only DNG changes??

Rhuarc

I'm going to quote an email that I sent to Mozy for some information, I'm wondering if anyone else has thought about or ran into these issues?

Hello!

I have been a user of Mozy Home for several months now, and really love it.
I did have a questiona bout how the software works though. I am using
Mozy to backup photos I take. I have recently started converting all the
shots I take from my cameras file type (CR2) into the Adobe Digital
Negative format. The difference here is that instead of the develope
information being kept in sidecard *.xmp files it is actually embedded in
the DNG file itself.

Before if I made a change on a picture such as a crop or something, it
would make a change to the sidecar *.xmp file (which is very small, several
KB) and Mozy would see that change and upload the sidecar file. I am
wondering how Mozy will treat the DNG files. Is it able to see that only a
small portion of a file has chnaged and only upload the small portion? The
reason I ask is this, if I go in to old photos and make a wholesale change
to even the EXIF (changing a keyword, for example) will Mozy reupload the
entire file, or will it be able to upload only the parts of the file that
have changed? If it is going to be reuploading the entire file I may need
to rething some of my workflow and backup strategies.

Thank you for your help and your incredible service!
Wendell Beitzel

Does this make sense to anyone? This would really only come into play when I go back and make mass updates, things like adding GPS info, changing my keyword structures, etc...

Just wondering what others here may think about this?

Pupator

They're going to say that the software will see that the file has changed and it will reupload the whole file.

It has no way of dealing with "parts" of files.

Rhuarc

Pupator wrote:

They're going to say that the software will see that the file has changed and it will reupload the whole file.

It has no way of dealing with "parts" of files.

THat is what I was afraid of, is there any software anyone knows of that can backup only the changed bits of a file? So if only the last 5 bits were changed the only those 5 bits would be copied?

This could be a real downer for DNG for me. The advantage to xmp in this case would be that since all the EXIF and XMP information are in a small little file, then no matter what changes I make, once the CR2 is backed up that won't ever need backed up again. Only the XMP would need to be uploaded.

Am I wrong in this?

claudermilk

I think you are correct. Heh, proof that eliminating those sidecar files isn't always the best idea.

Rhuarc

claudermilk wrote:

I think you are correct. Heh, proof that eliminating those sidecar files isn't always the best idea.

LoL, and I was SOOO happy when I saw what DNG could do with the embedded previews! LoL...

It's too bad there isn't a way to have a utility that could extract an xmp file from a DNG, and then later rewrite that xmp back to the dng file. In that way I could still use DNG files, but only backup the xmp changes.

I sanyone else who uses onlin ebackups running into this type of a problem?

bham

Its simple if you change the file in anyway it reuploads the file, with DNG then any updates to keyword, etc changes the file, so it gets reuploaded. With .CR2 and .xmp you are just changing the .xmp and it gets reuploaded. If you had a 200 page word document and changed one comma, then it would reupload the file because it was changed. The convience of the all in one file, you have found, also has drawbacks.