Differential backup is way too big...

[Agust]

Hi,

I have a DFS fileserver and it contains about 4.2 TB of data. Every day I do a full backup of a portion of the data and a differential backup of all of the data.

The fileserver services an office environment and most of the data (more than 80%) there is over two years old and never accessed.

Most days the differential is from 15-50 GB and that is okay but some days it jumps to 300 to 600 GB and I doubt that any one person is accessing or updating that much information.

Is there a way to find out what data this is short of restoring it?

Do you have any thought on what might cause so many files to seem new?

Best regards,
Agust.

[AmolB]

Open restore window and check the differential backup set, it will show what all files were backed up.

[Agust]

Okay but the files are quite distributed.

It is not easy to see a pattern in this view since for instance there are some files on everyones home directory that get updated every day or hour or something so it is hard to see where to look.

I am still trudgin through this but another approach would be nice if anyone has any suggestions.

[pkh]

It may be easier for your analysis to list the files in the backup using Cattools

http://www.symantec.com/docs/TECH136392

Do you have any anti-virus scans on your server?  This can cause the scanned files to be backed up as if they are modified.

[robnicholson]

Hi - that link doesn't work. Cheers, Rob.

[Ken_Putnam]

Works fine for me

[teiva-boy]

Why don't you buy the BackupExec 2010 File Archiving option?  It would remove the old files based on a policy you set (e.g. all files over 2yrs old)

It would move the files to an area of disk that is managed by BackupExec (internal, NAS, DAS, etc), and users will go to a website to search for their docs, either by file name, keyword, or even text in the message body too. Yes, it can scan and parse office files, pdf's, etc...

Not only would this shrink your full backups, but free up space, improve performance, and extend the life of your file server.