Backup disk failure

You would need a second external drive of equal or greater capacity than the one you want to backup. With both drives connected to your Mac, there are a few methods to create a backup:

1. (No cost) Via using the Disk Utility. Basically you will select the drive you want to back up, and then, restore it to the drive you want to back it up to.
2. (No cost) Via a series of commands in the Terminal app. The primary command would by the rsync command. It would looks something like the following: rsync -av --progress /Volumes/SourceDrive/ /Volumes/DestinationDrive/
3. (Free 30-day trial) Using a third party app, like Carbon Copy Cloner, to create a clone copy of the drive.

No matter which method you choose, the key is that the drive you need to backup, must be accessible. If it is not, then none of these methods will work ... and, if that data is critical to you, you may need to enlist the help from a dedicated recovery service.

Hmm ... I would have suspected that when plugged in directly, it should have appeared on the Mac's desktop.

A couple of things to check:

• Did you have to use an adapter (like a USB-A to USB-C) to connect this drive?
• In the Finder, is it configured to show External disks? (see image below)

Great! Let us know how it goes. Should you need any further assistance, just let us know as well.

Which exact model is your Mac? How about this new "Mac passport backup disk"? Would the latter be a Western Digital (WD) My Passport for Mac drive?

Thank you! I'm glad I was able to help.