Backing up to an external drive
The 90-day deleted file retention policy applies to both cloud destinations and local destinations. If you back up to an external drive as a local destination, files deleted from your computer will be removed from the local backup archive after 90 days.
Backing up from an external drive
When external drives are disconnected for any reason, the Code42 app marks the drive as “missing”. Missing files and folders within the drive are not marked as deleted, and CrashPlan will automatically scan and upload new versions of the files when the drive is reconnected. This also applies to internal drives that are disconnected (if you have any in addition to the hard drive your computer boots from).
However, an external drive could be marked as deleted if a new drive or device (like a USB stick) is connected under the name, drive letter, or path of the existing disconnected drive. This is because CrashPlan would consider it the same drive with different contents.
We recommend keeping external and internal drives connected whenever possible. If a drive must be disconnected, reconnect it to your computer regularly to ensure that CrashPlan can scan and upload new versions of the files.
If a drive is disconnected permanently because of failure, loss, etc., you can follow our instructions to Download files after replacing a drive.