Open your virus or malware software setting and ensure that your backup disk (“Backups.backupdb”) is excluded from automatic virus or malware scanning. If you are using malware or antivirus software on your Mac, it can cause this problem.If your Mac cannot pass this stage, then move to the next step below. What you can do is in the evening so that the backup can be completed overnight. The length of preparation time Time Machine needs may change due to a lot of factors such as the size of your backup.If you are experiencing this, try the steps below: When you go to System Preferences > Time Machine, you may see a message saying “Scanning xx items,” “Preparing,” or “Preparing backup” message. Sometimes you may experience an issue where a very long preparation phase may occur in Time Machine and it may seem to be stuck. And run First Aid on the Time Machine backup disk. You may want to repair it using Disk Utility. Ensure that your backup disk has enough available storage.

Select it in Finder and click Get Info.

It also supports the Mac OS Extended format (Journaled) format. APFS or APFS Encrypted disks are the preferred formats. Time Machine can’t back up to a disk formatted for Windows (FAT and NTFS).

Likewise, ensure that your disk file system is compatible with Time Machine.

Ensure that your backup disk is supported by Time Machine.

You can check for updates and update your Mac by going to System Preferences > Software Update.

Ensure that your Mac is running the latest version of macOS.

Make sure that your backup drive is properly connected (if you are using a network, ensure that your Mac and disk are on the same network) and turned on and plugged into a power source.

Restart your Mac and then try again (Apple menu > Restart).

There can be several reasons why you may have issues with it. Backups are great way to keep your data protected. Time Machine is Apple’s built-in backup technology.

How to backup my mac with time machine