What is backupd on a Mac? Time Machine's process, and why it uses CPU
backupd is Time Machine. It runs as root and works hard during a backup, especially the first. At rest on our Mac it used 0% and 2 MB. What drives it up.
What is backupd?
backupd is Time Machine's engine. It decides what changed, copies it to your backup disk and cleans up old backups. It lives in /System/Library/CoreServices/TimeMachine and runs as root.
On our Mac it had been running since start up, 30 hours, at 0.0% CPU with 2 MB: waiting for the next backup.
Why is backupd using so much CPU?
- The first backup to a new disk copies everything.
- After big changes: a large download, a new virtual machine, a photo import, a
node_modulesinstall. - Cleaning up: deleting old backups when the disk fills takes work too.
- Over the network: backups to a network disk are slower and keep it busy longer.
How do I make backups lighter?
Exclude what does not need backing up: open System Settings, General, Time Machine, Options, and add caches, virtual machines, build folders and downloads you can fetch again. Each excluded folder is work backupd never does.
tmutil statusShows whether a backup is running and how far along. A backup stuck on preparing is covered in the Time Machine in progress backup.
See it live
Free Mac's System tab ranks every process by processor use and energy impact, once a second, and marks the ones macOS will not let you quit as protected. See also Time Machine taking up space.
Related: trustd and syspolicyd high CPU.
Common questions
What is backupd on a Mac?
Time Machine's process. It copies changes to your backup disk and manages old backups. It runs as root.
Why is backupd using so much CPU?
A backup is running, often the first one or one after many files changed.
How do I reduce backupd's work?
Exclude caches, virtual machines and build folders in Time Machine's options.