Script to automatically remote old Mac OSX Time Machine Backups older than a specified number of days

tmcleanup.md

Prerequisites

• gfind (via brew install findutils)
• Time Machine drive mounted on your computer (or you can change path from standard /Volume/Time\ Machine\ Backups/Backups.backup.db/
• Admin/sudo access in the OSX terminal

Script

• Be sure to set the correct machine name. You can check the actual folder things are going into by looking in the backup location.
• By default, it erases all backups older than 30 days. Adjust as desired.

Usage

$ sudo ./tmcleanup.sh
*-* Removing old Time Machine Backups for vitruvius older than 30 days *-*
Deleting: /Volumes/Time Machine Backups/Backups.backupdb/vitruvius/2014-07-21-231955
Deleted (29.7G): /Volumes/Time Machine Backups/Backups.backupdb/vitruvius/2014-07-21-231955
Total deleted: 29.7G
Elapsed time: 2768 secs.
Finished!

tmcleanup.sh

#!/bin/bash
#
# Pre-requesite is that GNU linux findutils package is installed (brew install findutils) for gfind
# Should be possible to just use find but I have not tested it (should just omit -daystart)
#
BACKUP_LOCATION=/Volumes/Time\ Machine\ Backups/Backups.backupdb/
MACHINE_NAME=vitruvius
DAY_AGE=30

if [ ! -d "${BACKUP_LOCATION}" ]; then
	echo "${BACKUP_LOCATION} is currently not accessible. Please connect your Time Machine disk or change the path."
	exit
fi

echo "*-* Removing old Time Machine Backups for ${MACHINE_NAME} older than ${DAY_AGE} days *-*"
# Get a list of all the 
result=$(gfind "${BACKUP_LOCATION}""${MACHINE_NAME}"/ -daystart -maxdepth 1 -mindepth 1 -mmin +$((60*24*${DAY_AGE})))

echo "$result"

if [ -n "$result" ]; then
	while read -r line; do
		START_TIME=$(date +%s)
		tmutil delete "$line"
		END_TIME=$(date +%s)
		echo "Elapsed time: $(($END_TIME - $START_TIME)) secs."
	done <<< "$result"

	echo "Finished!"
else
	echo "Did not find any Time Machine Backups older than ${DAY_AGE} days old."
fi

$ tmutil machinedirectory
/Volumes/Time Machine Backups/Backups.backupdb/CBDesktop02

use tmutil machinedirectory command can simplify logic

To use BSD find without the need to install anything:

STARTDATE=$(date -v -${DAY_AGE}d +%Y-%m-%d)
result=$(find "${BACKUP_LOCATION}""${MACHINE_NAME}"/ -maxdepth 1 -mindepth 1 -not -newermt "${STARTDATE}")