File Exclude feature can be enabled/disabled for the Volume ("Limits" tab of Volume properties window). Read more in Creating Volumes.
1. Using the CDP Server web interface you can browse the files and folders on your Agent's hard disk and select the files and folders to include in the backup.
2. You can optionally add complex rules to exclude files by pattern. For example, *.log or *.mp3.
3. Your selected folders and exclude rules are communicated to the CDP Agent at the beginning of every backup operation.
4. CDP Agent (Windows and Linux) takes a point-in-time block level snapshot of the backup target.
5. The CDP Agent mounts the virtual snapshot device. For example, X: drive (Windows) or /mnt/snapshot (Linux).
These mounted devices are invisible to users and do not conflict with other mount points or drives.
6. According to the selected files/folders and exclude rules the Agent proceeds to delete all excluded files and folders from the writable snapshot using simple user space delete methods.
This deleting is only done in your point-in-time snapshot and does not affect your real disk volume and data.
See also: Excluding Files and Folders.