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Unmount a disk set or disk member
You may need to unmount a disk set or a member disk to repair it or perform other maintenance.
Unmount a disk set
In Disk Utility, select the disk set that you want to unmount in the sidebar.
Click the Unmount button
in the toolbar or beside the disk set name.
After unmounting a disk set, you can disconnect the disk members of the set from your computer.
Unmount a disk member of a set
In Disk Utility, select the disk set that you want to unmount in the sidebar.
Click the Unmount button
in the toolbar or beside the disk set name.
Disconnect the disk member that you want to unmount.
If you unmount and disconnect a disk, and then reconnect the disk later, Disk Utility rebuilds the disk member automatically if you selected “Automatically rebuild” when creating the disk set. If you need to rebuild the disk manually, see Repair a disk in a mirrored disk set.