Time Machine is the built-in backup utility of Macs. Aside from being free, it offers a simple way to back up all your files and programs and move them to another Mac as needed. However, as the contents of your Mac increases, they also require bigger backup space. When there is not sufficient storage for the backup file, Time Machine backup process may be interrupted or worse, corrupted. Of course, for every tech problem, there’s a solution. In this article, we will walk you through the measures to take when Time Machine for Mac fails due to lack of space. We’ll also show you how to reduce the size of your Time Machine backup file.
What to Do When Time Machine Backup Fails
As your Mac’s content grows in number and size, you are likely to see the following messages more often when Time Machine tries to back up your computer:
This backup is too large for the backup disk
Time Machine could not complete the backup
Back up requires _ GB but only _ GB are available
All of these messages mean that there is not enough space for Time Machine to perform its function. To the uninformed, the first solution that may come to mind is to get a new hard drive. However, that’s not entirely necessary. There are two workarounds you can try:
- Delete older backup files
- Change some information on the current backup so it will require less space
By the way, before you back up your Mac, take note of these reminders:
- Do not copy data, files, and information that you can practically do without to your backup drive as they will only consume storage space.
- Do not copy data, files, and information to your backup drive that will automatically be backed up by Time Machine anyway.
- Check if more than one Mac is using the drive you intend to use for backup. It is particularly necessary if you’re using a shared network attached storage (NAS) drive.
Deleting Old Time Machine Backups to Free Up Space
By default, Time Machine automatically deletes the oldest backup files whenever it creates a new one or when it detects that the disk assigned to it is already full. However, there will be times when you will have to do it manually yourself, especially when you are trying to back up a lot of information. Usually, when a user hasn’t made a Time Machine backup for a while, the resulting backup file will be huge. Moreover, even if Time Machine automatically deletes some of the older backups, the more recent ones might be left behind.
If you have a spare drive to use for the backup, you can use that. But if you don’t, then the easiest way to free up some space is to delete old backup files that Time Machine was unable to delete automatically. Here’s how to do it:
- Connect the drive to your Mac. Typically, it will mount on the Desktop.
- Open the drive to view the contents in Finder.
- Click on the folder with the name Backups.backups.
- The folders of the backed up files will be listed from oldest to newest.
- Select a folder/s you want to delete. It’s best to delete the oldest ones since you probably don’t need them any longer.
- Right-click or control-click on the folder. Click on Move to Trash.
- A warning that reads “You can’t undo this action. Do you want to move the backup to the Trash anyway?” will pop up. Click on Continue.
- Type in your password if asked.
- To make sure that the folder is completely deleted from the drive, go to the Trash. If you still see the folder/s there, right-click on it, then click Delete Immediately.
- Confirm that you want to delete the folder/s. Type in your password again when asked.
- Warnings that say it cannot be deleted because it or the drive is in use may pop up. Just click on skip and continue deleting.
Here’s another way to delete old Time Machine backup files:
- Click on your drive’s icon on the Desktop to see its contents in Finder.
- In the menu bar, click on Time Machine, then Enter Time Machine.
- Locate the backup you want to delete. Click on it.
- Click on the gear icon, then click on Delete All Backups of (folder name).
- A pop-up warning will show, asking if you’re sure you want to delete all backups of the selected folder permanently. Confirm the action by clicking OK.
- Enter your password when asked.
Deleting a Large File From a Backup
If you’re not comfortable with deleting an entire backup, but you believe that there is a huge file or folder that you don’t necessarily need yet was backed up by Time Machine, you can delete that instead of getting rid of the entire backup folder. Here’s how to do that:
- While the drive is connected to your Mac, open it in Finder.
- Find the item you want to delete from the backup folders.
- Click on Time Machine in the menu bar, then Enter Time Machine.
- Navigate to the time of backup that you want to delete, then click on the gear icon.
- Click Delete Backup.
- Type in your password when asked.
Excluding Items From Your Backup to Reduce Backup Size
If you want to keep the size of your Time Machine backup in check, you may specify which items to back up and which ones to ignore. To exclude items from being backed up by Time Machine, do these steps:
- Click Time Machine in the Finder menu.
- Click on Open Time Machine Preferences, then click on Options.
- You should see a list of items that are automatically excluded when you create a Time Machine backup.
- Click on the (+) icon to add more items to exclude from Time Machine backup.
Other Tips to Keep Time Machine Backup Size Small
To make sure that you don’t encounter any more problems during Time Machine back up related to lack of sufficient storage space, consider these tips:
- Do not back up your entire music library. Instead, sign up for iTunes Match. This way, your music library will be backed up in iCloud, allowing you to access your music anywhere.
- Instead of backing up photos in Time Machine, sign up for iCloud Photo Library.
- Make it a habit to clear your Mac of junk so that they won’t be included in your Time Machine backup. Apps such as Tweakbit MacRepair can help you get rid of junk in just one click.