Use CrashPlan to quickly back up to storage connected to your computer, such as a folder on your file system or an external hard drive directly attached via USB, Thunderbolt, Firewire, etc. CrashPlan calls this type of destination a folder.
Done! You are now backing up to the specified device.
Use CrashPlan to backup external drives in addition to the computer's primary drive to any available destination. Choose attached external drives in the same way you select files and folders for inclusion in your backup. When you choose an external drive, you are basically including the drive and its selected contents in your backup file selection.
Your drive will backup to the configured destination
CrashPlan uses absolute paths when backing up folders. If the name of a drive changes, CrashPlan will not see it and will list the drive as "Missing". You can fix this issue by renaming the external drive.