OS X Lion: Choose a backup disk and set encryption options
Follow these instructions to set up Time Machine, change to a different backup disk, or adjust other settings.
- Choose Apple menu > System Preferences, and then click Time Machine.
- Slide the switch to On if Time Machine is off.
- Click Select Disk.
- Choose a disk where backups will be stored, and click “Use for Backup.”
Every available disk that can be used to store backups is listed. If you partitioned a disk, the partitions are listed. Time Machine can’t back up to an external disk connected to an AirPort Extreme, or to an iPod, iDisk, or disk formatted for Windows.
If you select an NTFS or FAT formatted disk, Time Machine prompts you to reformat the disk. Choose a different disk, or reformat the disk in Mac OS Extended (Journaled) format. Because reformatting erases any files on the disk, do this only if you no longer need the files or have copies of them on a different disk.
- If the Encrypt checkbox is available, you can select it to keep your backup disk secure.
If the Encrypt checkbox is dimmed, your backup disk doesn’t support encryption.
Encryption is available only for partitions or disks attached directly to your computer and partitioned with the GPT partition scheme. If encryption is not available for your disk, put the mouse pointer on the dimmed checkbox, and after a moment an explanation appears. If a disk needs to be reformatted or repartitioned to support encryption, Time Machine prompts you to do so.
- If you select Encrypt, type a password and password hint for the backup disk.
After encryption is turned on, you’ll need to provide the password when you connect the backup disk to your computer. You will not need to provide the password again unless you disconnect the disk or restart your computer.
Time Machine works best if you use your backup disk only for Time Machine backups. If you keep files on your backup disk, Time Machine won’t back up those files, and the space available for Time Machine backups is reduced.