could not unmount disk external hard drive

If you're unfamiliar with the vi editor in Terminal, select all of the text above and copy it. Adjust the times accordingly, particularly the unmount time if you have longer backups. The second line will unmount the disk at 4:15am. Replace the end of the second line, '/Volumes/The Annex' with '/Volumes/name of your backup hard drive' (the quotes will handle any spaces in the drive's name).Īssuming that I do a backup at 4am, the first line will mount the disk at 3:59am. Replace the end of the first line, disk1s10 with the drive identifier from step one. Edit your crontab to contain the lines:ĥ9 3 * * * /usr/sbin/diskutil mount /dev/disk1s10ġ5 4 * * * /usr/sbin/diskutil eject '/Volumes/The Annex'.Select Info, and make note of the Disk Identifier.With the drive mounted, open Disk Utility and select the drive partition that will be the destination of the backup.Instead, I prefer to mount/unmount the drive just prior to and after Backup runs, so that's it's not in the way when I don't need it. Problem is that I don't like having it mounted all of the time, since it spins up whenever I save or open a document, etc. I use Apple's Backup program to back up files from my computer every night to an external hard drive (that has only one partition) reserved for backups.

Could not unmount disk external hard drive