The hard disk where you store Time Machine may be full or it may be old. So its failure will lead to the loss of all backups of your system. In any case, you will have to transfer Time Machine files from one hard drive to another.
Good news! It’s pretty simple. It is only necessary to correctly format the new hard disk and set a new path for saving backup files.
Single External Hard Drive for Time Machine Backups
- Go to System Preferences -> Time Machine;
- Remove the check mark next to the line “Back Up Automatically”;
- Next connect a new hard drive;
- Most likely, it is incorrectly formatted, so we run Disk Utility;
- Select the hard disk in the left column and click Erase;
- Select the formatting “Mac OS Extended (Journaled)”;
- Click Erase. Warning: All media data will be deleted from this hard drive!
- When the disk is ready, go back to the System Preferences -> Time Machine;
- Choose Select Backup Disk and then click on your External HDD in a list;
- You will be asked if you want to change the hard drive or use both. Click “Use Disk”, unless you need for any reason to use both backups;
- Then we return a tick for the line “Back Up Automatically” and you can start.
In general, this is quite simple: you need to take an external hard drive, attach it to your Mac, and he should ask himself if you want to use this drive to backup Time Machine.
Read more: How to Check Hard Drive Health in macOS?
Important advice: make the first backup in the evening, because for the first time, the process can take all night, especially if you have a lot of data on the disk.