Mac Basics: Time Machine backs up your Mac
Learn how to set up Time Machine to perform backups, how to restore items, how to use System Restore to return your entire Mac to a specific date, how to migrate backups to a new Mac, and more.
Time Machine is the built-in backup feature of OS X that works with your Mac and an external drive (sold separately) or AirPort Time Capsule. Connect the drive, tell Time Machine to use it, and relax. Time Machine automatically backs up your entire Mac, including system files, applications, accounts, preferences, email messages, music, photos, movies, and documents. But what makes Time Machine different from other backup applications is that it not only keeps a spare copy of every file, it remembers how your system looked on any given day—so you can revisit your Mac as it appeared in the past. Time Machine keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups until your backup drive is full.
OS X Lion and later let you:
- Encrypt your Time Machine backup.
- Start from OS X Recovery using your Time Machine backup disk. With OS X v10.7.3 and later, Time Machine backs up the Recovery System on your Mac to your backup drive as well. This lets you use your Time Machine drive to start up your Mac if needed. Simply connect your Time Machine drive, then hold down the option key at startup to select it as your startup disk.
OS X Mountain Lion and later let you:
- Encrypt AirPort Time Capsule backups and network backup.
- Select multiple backup destinations that Time Machine will rotate through for backup cycles.
- Complete backups when the Mac is in Power Nap (on compatible Macs).
OS X Mavericks lets you:
- Stay informed of your initial backup status using Notifications. Time Machine displays a notification after the first backup is complete, or if any issues arise during the initial backup.
Time Machine menu
The Time Machine menu in the menu bar also lets you know when a backup is happening in the background. While a backup is in progress, the menu icon includes an additional arrow in Mavericks, or rotates counterclockwise in earlier versions of OS X.
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You can check the status of your backup by clicking on the Time Machine icon in the menu bar. If you see a Time Machine icon in the menu bar that indicates a possible issue, click the icon to learn what is preventing Time Machine from backing up.
Note: You can also select this menu while holding down the Option key to see additional options: verify your backup disk, or manually select a different backup disk to browse.
For additional information about setting up and using Time Machine, select one of the topics below.
If your backup drive fills up
As your backup drive begins to fill up to its capacity, Time Machine intelligently deletes the oldest backups to make room for newer ones. It also alerts you if the “Notify after old backups are deleted” option is selected in Time Machine preferences.
Consider the following options if your backup disk is filling up often, causing your oldest available backups to be erased sooner than you might want:
- Use additional drives for your backups, or transfer your backups to a new, larger drive using the steps in Time Machine: How to transfer backups from the current backup drive to a new backup drive.
- Tip: You can also browse the original backup drive for past backups by using “Browse other Time Machine Disks”–to see this choice, hold the Option key then click the Time Machine menu in the Finder (to see the menu, “Show Time Machine status in the menu bar” must be selected in Time Machine preferences.
- Reduce the amount of information being backed up by adding to the “Exclude these items from backups” list in Time Machine preferences, as mentioned above. Your backup drive will fill up less often.
- Delete file(s) that are no longer needed (such as from your desktop, Documents folder, or other Home folder locations), so they will no longer be backed up. You can also enter the Time Machine restore interface and find files that can be removed from the backup drive itself to conserve space. To do this, select the file(s) and from the Action pop-up menu (gear icon) in the Time Machine Finder window choose “Delete All Backups of…”. Be sure to only delete files you are sure you won’t need or want to restore later.