This utility is an update to a blog post that aimed to help OS X users verify external Time Machine disks and overcome a diskutil deficiency.
The blog entry notes that a user can use the graphical Disk Utility in a certain order to unmount the Time Machine volume and then use the utility to "Repair" the volume.
Unfortunately, even after unmounting the volume OS X leaves what I think are local snapshots mounted that reference the external volume. They are of the form:
com.apple.TimeMachine.2021-08-31-103804.backup@/dev/disk7s2 on /Volumes/ . . . . . . .
Thus, the Repair operation fails.
This utility manually unmounts those pesky time machine volumes
Usage
peskytm --help
Usage: peskytm.py [OPTIONS]
Options:
--version Show the version and exit.
--help Show this message and exit.
Notice this utility has no parameters. You simply execute it. Internally, peskytm use sudo, so you will be prompted for your OS X password (Don't worry the utility does nothing but pass it along). You will then see output like the following:
peskytm
com.apple.TimeMachine.2021-08-31-103804.backup@/dev/disk7s2 unmounted
com.apple.TimeMachine.2021-09-09-221954.backup@/dev/disk7s2 unmounted
com.apple.TimeMachine.2021-09-16-141610.backup@/dev/disk7s2 unmounted
com.apple.TimeMachine.2021-09-26-120444.backup@/dev/disk7s2 unmounted
com.apple.TimeMachine.2021-10-06-172708.backup@/dev/disk7s2 unmounted
com.apple.TimeMachine.2021-10-14-144954.backup@/dev/disk7s2 unmounted
Once you manually unmount this pesky volumes you can either use the graphical utility or the command line utility (CLI). An example, usage of the CLI is:
sudo fsck_apfs -y /dev/disk7s2
pipx install peskytm