If you use Time Machine to backup a Mac to an external drive, you may decide to manually delete old backups that are no longer needed. Yes, Time Machine does it’s own housekeeping, but sometimes users need to manually intervene. This can be for a variety of reasons, whether for simple removal of old backups, or if you eventually run into space limitations on a backup drive where Time Machine triggers an error saying “Time Machine could not complete the backup. This backup is too large for the backup disk. The backup requires XX GB but only YY GB are available.”

Whatever the reason, you can easily delete old backups from a Time Machine drive to either free up space on that drive for a new backup, or just to perform some manual house keeping of a Time Machine drive.

Deleting Old Backups of Time Machine via Time Machine in Mac OS X

This is the preferred approach to deleting old backups made in Time Machine, it uses the Time Machine application itself and is simple, handled entirely through the friendly user interface.

Connect the Time Machine drive to the Mac if you haven’t done so yet Pull down the Time machine icon in the menu bar, then choose “Enter Time Machine” Navigate to the point in time you want to delete (if it’s a very old backup you’re looking to delete, scroll until you find the appropriate place in time) Right-click on the backup in the Finder window of Time Machine, or click on the little gear icon in the Finder window – both work the same – then choose “Delete All Backups of (Name)” Enter the admin password when requested to delete the backup

Essentially you’ll be navigating to the section of the Mac file system that you want to delete a time machine backup for, thus if you want to delete old backups for the entire Mac, navigate to the root folder, or the user folder, whichever is appropriate for your scenario. In this way, the process of deleting an entire old backup is similar to deleting a backup of a specific file or folder from Time Machine, except that rather than targeting a small portion of the file system, you choose the entire Mac or the user directory within Time Machine.

Deleting Old Backups from Time Machine with tmutil

If you’re savvy with the command line, the tmutil utility can also remove backups of any age immediately. The GUI approach above is much easier for most users as it gives a visual representation of what will be deleted, whereas tmutil is only appropriate for those with sufficient terminal experience. As always with the command line, exact syntax is essential.

The tmutil syntax to use is as follows:

tmutil delete /TimeMachine/Drive/Path/To/OldBackup/

You’ll likely want to list out the directories by date to see which old backup to delete so that you can be sure you have the proper path in place. Using tab completion could skip this if you’re certain, otherwise just use ls to see a list of dates:

ls /Volumes/TimeMachineDrive/Backups.backupdb/MacName/

This list can be quite long and specific.

For example, if you have an old backup from a few years ago you wish to remove on a specific date:

tmutil delete /Volumes/BackupDriveName/Backups.backupdb/MacComputerName/YYYY-MM-DD-HHMMSS/

Be sure to change “BackupDriveName” to the drive name of the Time Machine volume, “MacComputerName” to the name of the Mac you wish to delete the backups from, and the precise date in Year / month / date / time format by replacing “YYYY-MM-DD-HHMMSS” as necessary.

An example of such syntax would be:

sudo tmutil delete /Volumes/Time Machine Backups/Backups.backupdb/MacBook\ Pro/2015-07-13-150021/

Again, be sure to use exact syntax.

Like other command line tools, tmutil can accept wildcards, meaning you could technically delete all backups this way. Just be sure you know what you’re doing otherwise you may lose data you did not intend to. Unless you make backups of your backups (with Time Machine redundancy or otherwise) that would be impossible to recover from.

(Important Sidenote: Surely some advanced Mac users are wondering why not just use rm -rf or drop it into the trash and force empty. While both of those methods will work to delete the backup, it almost always results in a broken Time Machine backup or at best Time Machine gets stuck on “Preparing Backup” which requires further troubleshooting. To avoid that, skip rm and skip using the Trash to delete old Time Machine backups, use the Time Machine app, or tmutil tool)

Typically removal of old backups is only necessary for very specific maintenance reasons for a backup disk, or to free up space from antiquated backups. Rarely, this can be necessary as a troubleshooting trick too, which is usually caused by a hiccup on the most recent backup file.

Whichever method you go with, it is highly recommended to manually start a new backup immediately after deleting other backups, this insures you have a recent backup available, and is particularly important if you just deleted a lot of old backups for a specific Mac.

