CrashPlan uses a proprietary encrypted and compressed format to store backup archives. These archives are automatically excluded from your backup selection—you cannot use CrashPlan to back up a CrashPlan backup archive.
This article discusses why you can’t back up your CrashPlan backup, as well as options for backing up files created by other backup software and cloud services.
CrashPlan is most efficient at backing up your original files. By encrypting and compressing the files on your computer, CrashPlan creates a dense archive for storage. Including the entire archive again in your backup selection has several drawbacks:
- Increased system resources required to re-compress and re-encrypt the archive
- Inability to use real-time backups
- In order to access a single file, you would need to restore the entire archive, which could take a very long time
- Archive maintenance cannot be performed properly
Due to these restrictions, we automatically exclude CrashPlan archives from your backup selection. If you want additional copies of your archive for redundancy, consider backing up to multiple destinations.
Time Machine and other backups
CrashPlan and Time Machine complement each other very well and can be used side-by-side. However, backing up your Time Machine archives with CrashPlan is not recommended for technical and practical reasons.
You may be able to back up archives created by other backup applications with CrashPlan. However, there are special considerations for backing up really large files. Additionally, if the software uses soft or hard links to create the backup archive, it can create conflicts with the processing of your CrashPlan archive. Consult the manufacturer's documentation to determine whether or not the service is compatible with CrashPlan.
Other cloud services
Though they are not strictly backups, you may want to ensure that you have a backup of the data that you have stored on other cloud services. See Backing Up Cloud Services for more information.