

The erased volume is written seven times to ensure the data can't be restored. Department of Defense (DOD) 5220-22M standard for securely erasing magnetic media. Most Secure: This method of securely erasing a volume or disk meets the requirements of the U.S.It writes two passes of random data to the volume or disk and then writes a single pass of a known data pattern to the volume or disk. Three-Pass: This is a DOE-compliant three-pass secure erase.Show more Show more How To Format an External Hard Drive for. Advanced recovery techniques could restore the data, but it would require a great deal of time and effort. How to format a MAC formatted drive to NTFS for it to work on Windows 10 and other versions of Windows that read NTFS. Zero Out the Data: This erase method writes a single path of zeros to all locations on the selected volume or disk.It doesn't scramble the file data, which means a recovery app may be able to resurrect the erased data. Fastest: This is the quickest erase method.

The drop-down Secure Erase Options menu presents options similar to the ones in earlier versions of the operating system, but it uses a slider for making choices instead of an options list. Options for OS X Lion Through OS X Yosemite

Don't expect this erase method to finish any time soon. It writes over the data on a volume 35 times.
