tmstart.sh

#!/bin/zsh -ef

export PATH=/bin:/usr/bin:/usr/sbin:/usr/libexec
setopt extendedglob

diskutil unmount $(diskutil list | awk '/MaryBackup\+ A/ { print $NF }')

[[ $(id -u) == 0 ]] || { print "$0: must be running as root" >&2 ; exit 1 }

# enable AppleFileServer
launchctl load /System/Library/LaunchDaemons/com.apple.AppleFileServer.plist

# enable backupd
defaults write /Library/Preferences/com.apple.TimeMachine AutoBackup -bool YES