Forum Discussion

jukeboxjoe's avatar
10 years ago

Incremental backup on Backup Exec 2010 byte count increased dramatically without explanation

I'm running Backup Exec 2010 in a Server 2008 environment. We run a full backup once a week and run an incremental job to backup the changed files on the other weeknights,  A full backup byte count is typically 7.6 TB and the incremental ranges between 120-160GB growing in size as the week goes on.

Last week on the Thursday backup the incremental size increased without warning or explanation.  The Wednesday backup was 134GB and the Thursday backup was over 2 TB. The following nights backup was 2.5TB. The fulll backup at the weekend was 7.6TB which was the normal expected size.

The daily incremental last night was 1.6TB.

We have not added any large amount of data or made software changes.   I have no explanation for this.  Any ideas or suggestions?


I have attached a screenshot of the recent backup job activity.

3 Replies

  • Compare the job logs or use the CatDump utility to check which resources (and their sizes) have been backed up -

    Additionally, if running any AV, set it to exclude from scanning the BE processes and check if there any other non-BE backups configured or not.

  • Please check your selection list for the resources you are backing up. If you have a local B2D folder to store the backed up data, then exclude it from the backup selection.

    Also, check that both, Full and Incr backups are using same backup method - either Archive Bit or Modified Time i.e. don't keep full backup running using the archive bit and incr backup using modified time or vice versa.

    Please refer these articles for more information:

    Backup methods in Backup Exec

    About the archive bit and backup methods

    About modified time and backup methods


  • If you are using the modified time method and you have AV scans on your server then you can expect big incremental out differential backups. See my blog below if you are using SEP If you are using other AV, check with the vendor whether a similar thing will happen