Synchronizing is part of the normal operation of CrashPlan as it's a file verification scan, which compares the data on your computer against the data on our servers.
This scan looks like it is backing up your data again, but will go much faster. This is done to ensure that the information selected to be backed up is actually backed up and can be reliably restored. This is a regular process of the software which can take between 5 seconds to 24 hours to process as it depends on the speed of your computer and it's hard drive.
If you switch your computer off or let it go to sleep it will restart the process, so please leave your computer running until this is finished.
Synchronizing can also run after the following:
- If you update your computer i.e. upgrading Apple OS X to Mountain Lion
- If you make major changes to CrashPlan PROe i.e. changing the backup selection
- After the Archive Maintenance routine has run
- If you reinstall CrashPlan PROe
- Or change the backup version
If CrashPlan detects any problems with the files or blocks that has been selected to be backed up, it will request them again as part of the self healing process.