Erase an AirPort Time Capsule in AirPort Utility on Mac
If you’re using an AirPort Time Capsule, you can use AirPort Utility to erase its disk.
Open the AirPort Utility app on your Mac, located in the Utilities folder in the Applications folder.
In the graphical overview, select the Time Capsule you want to erase, then click Edit. You may need to enter a password for the Time Capsule.
Click Disks, then click Erase Disk.
Click the Security Method pop-up menu, choose a security level, then click Erase.
You can choose the following levels of security when erasing the internal disk:
Quick Erase (non-secure): Quick Erase erases directory information from the disk so that the data is no longer accessible. The data remains on the disk until additional data is written over it. Data can be recovered, so this choice is the least secure.
Zero Out Data: This option writes zeros over all the data on the disk. Zero Out Data provides good data protection in a short amount of time. This option overwrites the entire disk, so it takes longer than the Quick Erase option.
7-Pass Erase: This option writes zeros over the entire disk seven times. 7-Pass Erase is highly secure, but it takes seven times longer than the Zero Out Data option.
35-Pass Erase: 35-Pass Erase provides the most security. It writes zeros to the entire disk 35 times, and takes 35 times as long as the Zero Out Data Option.
Click Update to save your changes.
The AirPort Time Capsule status light flashes amber while the disk is being erased. You won’t be able to change settings, update the firmware, or restart the AirPort Time Capsule until the disk is erased and becomes available again.