European Union Flag
European Apple Users Information & Support
LOGIN
The next event is:
IFSEC 2024

From 2 December 2024
to 4 December 2024
More events…

macOS 14 Sonoma
FREE
Amazon UK Mac Software Affiliate Link
I love Quidco

Formatting / Partitioning / (Securely) Erasing A Hard Disk Or Volume

Article ID = 37
Article Title = Formatting / Partitioning / (Securely) Erasing A Hard Disk Or Volume
Article Author(s) = Graham Needham (BH)
Article Created On = 13th July 2011
Article Last Updated = 20th October 2017
Article URL = https://www.macstrategy.com/article.php?37

Article Brief Description:
Instructions for Formatting / Partitioning / (Securely) Erasing A Hard Disk Or Volume

Formatting / Partitioning / (Securely) Erasing A Hard Disk Or Volume

NOTE: These processes can be used for multiple types of storage hardware including hard disks, Sold State Drives (SSDs), SD cards or USB sticks/flash drives.
NOTE: This process will erase your selected volume / storage device and wipe all data from it.
NOTE: Remember to de-authorise/deactivate any software/services on the drive if it was used as a system disk.
Authorised/Activated Software and/or Services
NOTE: If you know of any other Macintosh software that requires activation please contact us.
Follow these instructions:
  1. If you are not booting from a Mac OS X installation disc or external installation device, to be safe:
    • Restart your computer.
    • Quit all running applications.
    • Disconnect all external devices except for monitor, keyboard, mouse and required storage volumes.
    • Eject all optical discs.
    • Unmount all servers.
  2. If you are not formatting an internal hard disk or SSD, connect or insert your storage device now.
  3. Go to Macintosh HD > Applications > Utilities > Disk Utility.
NOTE: If you are setting up an SD card or USB stick/flash drive as a boot drive or external installation device follow the instructions under "To Partition A Device" below.
NOTE: USB boot drives or USB external installation devices only work on Intel Macs.
NOTE: A "volume" is a single partition. A "device" is the whole storage device that may contain one or more partitions (volumes). Individual volumes can have different names and usually mount on the desktop with their own icon (if this is turned on in Finder > Preferences > General > "Hard Disks" and "External Disks" ticked)
NOTE: Special information on using drives that are larger than 2TB.
NOTE: Special information on using Advanced Format Technology (AFT) drives.

To Erase A Volume or Device with One Partition

NOTE: This process will erase your selected volume / storage device and wipe all data from it.
NOTE: Remember to de-authorise/deactivate any software/services on the drive if it was used as a system disk.
  1. On the left select the volume or device (with one partition) that you want to erase
  2. NOTE: with OS X 10.11 or later you can only erase a volume.
    NOTE: with macOS 10.13 or later Disk Utility only shows volumes by default and the Sidebar can be hidden - go to View menu > Show Sidebar and View menu > Show All Devices to see everything.
  3. On the right click on the "Erase" tab.
  4. Disk Utility - Erasing A Volume
  5. Select the format, usually:
  6. Enter the "Name" for your volume (if it's your main boot disk it's usually "Macintosh HD").
  7. If you have a PowerPC Mac running Mac OS X 10.4 or earlier that is capable of booting Mac OS 9 and you still want to be able to boot into Mac OS 9 tick the "Install Mac OS 9 Drivers" option.
  8. Click "Erase…".

To Securely Erase A Volume or Device with One Partition

NOTE: This process will erase your selected volume / storage device and wipe all data from it.
NOTE: Remember to de-authorise/deactivate any software/services on the drive if it was used as a system disk.
NOTE: We do not currently recommend securely erasing an SSD!
  1. On the left select the volume or device (with one partition) that you want to erase
  2. NOTE: with OS X 10.11 or later you can only erase a volume.
    NOTE: with macOS 10.13 or later Disk Utility only shows volumes by default and the Sidebar can be hidden - go to View menu > Show Sidebar and View menu > Show All Devices to see everything.
  3. On the right click on the "Erase" tab.
  4. Disk Utility - Erasing A Volume
  5. Select the format, usually:
  6. Enter the "Name" for your volume (if it's your main boot disk it's usually "Macintosh HD").
  7. If you're erasing a device and have a PowerPC Mac running Mac OS X 10.4 or earlier that is capable of booting Mac OS 9 and you still want to be able to boot into Mac OS 9 tick the "Install Mac OS 9 Drivers" option.
  8. Click the "Security Options…" button.
  9. Disk Utility - Secure Erase Options With OS X 10.9 And Earlier Disk Utility - Securely Erasing A Volume OS X 10.9 and earlier Disk Utility - Secure Erase Options With OS X 10.10 And Later Disk Utility - Securely Erasing A Volume OS X 10.10 and later
  10. Choose your desired level of security for the erase.
  11. NOTE: Some of the security levels are only available with certain versions of Mac OS X e.g. Mac OS X 10.4 or later. OS X 10.10 and later offers:
    • Fastest = quick format
    • > 2 pass (random data + zeroes)
    • > DOE-compliant 3 pass (2 passes of random data + single pass of known data)
    • Most secure = US DOD5220-22 M (writes over the data 7 times)
    NOTE: Securely erasing a volume can take a HUGE amount of time with the large storage capacities that are now available i.e. many hours if not actual days!
  12. Click OK and then "Erase…".

To "Format" A Device

NOTE: This process will erase your selected volume / storage device and wipe all data from it.
NOTE: Remember to de-authorise/deactivate any software/services on the drive if it was used as a system disk.
  1. On the left select the device that you want to format.
  2. NOTE: with macOS 10.13 or later Disk Utility only shows volumes by default and the Sidebar can be hidden - go to View menu > Show Sidebar and View menu > Show All Devices to see everything.
  3. On the right click on the "Partition" tab.
  4. Select "1 Partition" from the 'Volume Scheme' pop-up menu - in OS X 10.11 or later you can set the number of partitions you want using the + and - buttons (use the - button to change it to 1 partition).
  5. Disk Utility - Format A Device
  6. Enter the "Name" for your volume (if it's your main boot disk it's usually "Macintosh HD").
  7. Select the format, usually:
  8. If you have a PowerPC Mac running Mac OS X 10.4 or earlier that is capable of booting Mac OS 9 and you still want to be able to boot into Mac OS 9 tick the "Install Mac OS 9 Drivers" option.
  9. Click "Apply".

To Partition A Device

NOTE: This process will erase your selected volume / storage device and wipe all data from it.
NOTE: Remember to de-authorise/deactivate any software/services on the drive if it was used as a system disk.
  1. On the left select the device that you want to partition.
  2. NOTE: with macOS 10.13 or later Disk Utility only shows volumes by default and the Sidebar can be hidden - go to View menu > Show Sidebar and View menu > Show All Devices to see everything.
  3. On the right click on the "Partition" tab.
  4. Select your desired number of partitions (volumes) from the 'Volume Scheme' pop-up menu - in OS X 10.11 or later you can set the number of partitions you want using the + and - buttons.
  5. NOTE: Each volume can be of different size and format (by default Disk Utility will size partitions equally from the available storage capacity - you can either resize by dragging the partition shape/slider on the circle or by entering the required amount for "Size"). Disk Utility - Partition A Device With OS X 10.10 Or Earlier Disk Utility - Partition A Device With OS X 10.10 Or Earlier Disk Utility - Partition A Device With OS X 10.11 Or Later Disk Utility - Disk Utility - Partition A Device With OS X 10.11 Or Later
  6. Enter the "Name" for each partition or volume (if it's your main boot partition it's usually named "Macintosh HD").
  7. Select the format, usually:
  8. If you have a PowerPC Mac running Mac OS X 10.4 or earlier that is capable of booting Mac OS 9 and you still want to be able to boot into Mac OS 9 tick the "Install Mac OS 9 Drivers" option.
  9. Click the "Options…" button.
  10. Disk Utility - Formatting Options
  11. Choose your desired partition scheme for this device
  12. NOTE: Partition schemes are only available with Disk Utility on later versions of Mac OS X e.g. Mac OS X 10.4 or later.
    • GUID Partition Table = To be able to boot an Intel Mac
    • Apple Partition Map = To be able to boot an PowerPC Mac or Intel Mac
    • Master Boot Record = To be able to boot a DOS or Windows computer
    • NOTE: If you are going to use the storage device:
      • not as a boot disk select "Apple Partition Map".
      • not as a boot disk but only on Mac OS X 10.4 or later select "GUID Partition Table".
      • as a boot disk but only on Mac OS X 10.3 or earlier select "Apple Partition Map".
      • as a boot disk on a PowerPC (G3, G4, G5) Mac select "Apple Partition Map".
      • as a boot disk but only on an Intel Mac select "GUID Partition Table".
      • as a boot disk but for both PowerPC and Intel Macs select "Apple Partition Map" e.g for an Emergency Boot Disk.
      • as a boot disk but only for Windows select "Master Boot Record".
      • as a boot disk and it is an SD Card or USB stick/flash drive select "GUID Partition Table".
  13. Click OK and then "Apply".


Article Keywords: Mac OS X OSX 102 103 104 105 106 107 108 109 1010 1011 macOS 1012 1013 1014 1015 1100 1200 1300 1400 Jaguar Panther Tiger Leopard Snow Leopard Lion Mountain Lion Mavericks Yosemite El Capitan Sierra High Sierra Mojave Catalina Big Sur Monterey Ventura Sonoma format erase partition hard disk drive storage device secure securely Macintosh

This article is © MacStrategy » a trading name of Burning Helix. As an Amazon Associate, employees of MacStrategy's holding company (Burning Helix sro) may earn from qualifying purchases. Apple, the Apple logo, and Mac are trademarks of Apple Inc., registered in the U.S. and other countries. App Store is a service mark of Apple Inc.


If this information helped you or saved you time and/or money why not donate a little to us via PayPal?
All proceeds go directly to MacStrategy / Burning Helix to help fund this web site.
If this information helped you or saved you time and/or money why not donate a little to us via PayPal?
All proceeds go directly to MacStrategy / Burning Helix to help fund this web site.

Go to this
web page
to donate to us.