How can I fix the Mac OS System external drive name?

From a CNET story in 2011 but worked for me....

When you eject a drive, the system should remove the mount point for the drive; however, sometimes this doesn't happen. Crashes or other improper ejecting of drives can sometimes cause the system to leave the drive's mount point in the hidden /Volumes directory, and then when you attach the drive again the system recognizes an existing mount point of the same name and will append a number to the new mount point.

To clear this problem, unmount all drives and go to the hidden /Volumes directory by entering the text "/Volumes" in the Finder's Go to Folder option (available in the Go menu). This should open the mount points directory, and if you see any folders, aliases, or other files in the directory that have the same name as your external drive, then remove them.

Eject it and mount it again. That usually happens if the system creates a folder where the drive disappeared. When you mount it again, it has to create a new mount point with a different name.

Is there a BackupDrive folder there?

To be safe I would unmount my drive and perhaps unplug it! Then take a look at the /volumes directory to see if there is a reference to your drive still.

This is one of the reasons to "UNMOUNT" or EJECT and not just unplug. I believe when you unmount it will delete the reference to your drive in the /Volumes folder

dversion wrote:

This is one of the reasons to "UNMOUNT" or EJECT and not just unplug. I believe when you unmount it will delete the reference to your drive in the /Volumes folder

I would add that a user should wait a minute after ejecting the drive before unplugging it from the computer (or wait until the activity LED on the drive stops blinking)...sometimes macOS takes a while to unmount/eject a drive. I really miss the old days when macOS actually told a user when it was safe to disconnect a drive...most times you can probably disconnect a drive after waiting 15 seconds, but it all depends.

You may need to reboot the Mac again. I recommend that you first eject the external drive first before rebooting.