How to fix the Time Machine backups not finishing problem on macOS High Sierra

There is a bug in macOS High Sierra (10.13) which prevents Time Machine backups from completing. If your backups aren’t finishing, then you might have this problem. To see if you do, open up Terminal in /Applications/Utilities/ and run this command

log show --style syslog --predicate 'senderImagePath contains[cd] "TimeMachine"' --info

If you see messages like this:

2018-01-26 13:31:35.269569+0100  localhost backupd[2082]: (TimeMachine) [] Failed to unmount disk mounted at '/Volumes/', error: {
    Action = Unmount;
    Target = "file:///Volumes/";

2018-01-26 13:31:35.269970+0100  localhost backupd[2082]: (TimeMachine) [] Failed to unmount snapshot: source: MacintoshHD
2018-01-26 13:31:36.322938+0100  localhost backupd[2082]: (TimeMachine) [] Backup canceled.

Then it is likely that you have this problem.

To finish a backup, you have to temporarily disable Spotlight. To do this you must first disable SIP (System Integrity Protection). Restart your computer, and once it is booting hold +R to boot into recovery mode. Open the Terminal from “Utilities” in the menu bar and disable SIP through this command:

csrutil disable

Then reboot, and again open Terminal and run this command to disable Spotlight:

sudo launchctl unload -w /System/Library/LaunchDaemons/


Barring other problems, you should be able to finish your backup after this. To enable Spotlight again, run this command:

sudo launchctl load -w /System/Library/LaunchDaemons/

To enable SIP again, you can either reboot into recovery mode and run:

csrutil enable

or just reset your NVRAM. To reset your NVRAM hold +alt+P+R during boot.