File and Folder Exclude Architecture

1. Using the CDP Server web interface a user browses the files and folders on their Agent's hard disk.  They select (check boxes) next to the files and folders they want to include in their backup.
    
2. User optionally adds complex exclude rules allowing them to define rules that exclude files by pattern.  For example *.logs or *.mp3 (really simple examples).
    
3. The user's selected folders and exclude rules are communicated to the CDP Agent at the beginning of every backup operation (aka synchronization in 3.0)
    
4. CDP Agent (Windows and Linux) takes a point-in-time block level snapshot (VSS on Windows and /dev/cdp on Linux) of the backup target (e.g. hard disk / RAID array / ISCSI / software RAID etc)
   THE MAGIC IS THIS POINT-IN-TIME SNAPSHOT in CDP 3.0 IS READ / WRITE!   
   Note: CDP 2.0 Linux Snapshots and MS VSS snapshots (Without CDP 3.0) are READ-ONLY!
    
5. The CDP Agent mounts the virtual snapshot device.  E.g. X: drive in Windows or /mnt/snapshot (Linux). 
   Note: don't worry we have special tricks for making these mounts invisible in a way they won't ever conflict with other mount points or drives
     
6. According to the selected files/folders and exclude rules the Agent proceeds to delete all exclude (opposite of included) files and folders from the writable snapshot using simple user space delete methods.  (Think "rm -Rf /unwanted/directory" or "find "exclude-patern" -exec rm {}\;")
   Note: This deleting is only done in your point-in-time snapshot and in no way affects your real disk volume and data!  Get it?  Its Magic!

R1Soft Writable Volume Shadow Copy Device Driver Design

R1Soft Writable Linux Snapshot Device Driver Design