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User profile for user: Ziphoid
Ziphoid Author
User level: Level 1
17 points

Help with new iMac Please

I am awaiting the arrival of my new 27 inch iMac, being techno illiterate I have been researching how to remove my data from the original iMac.  I use a LaCie external HDD as a time machine back up so presume my data is safe!  I have transferred many of my old family photos and videos, along with several other files, onto the LaCie as there is 2TB of space on it and it reduces the usage on the HDD.  My problem is that during research I am advised to erase the Mackintosh HD, unfortunately when I open disc utility the only item erasable is Apple HDD, should I erase this after transferring data?  I have attempted to include a screenshot.


Posted on Jan 24, 2021 3:40 AM

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User profile for user: Jack-19
Jack-19
User level: Level 8
46,002 points

Posted on Jan 24, 2021 5:53 AM

Hi Ziphoid,


What ekorko said is correct, but here is my guide for further information to erase your Mac and reinstall macOS:


  1. Backup all DATA! When you do this, all your data will be erased! This action cannot be undone! Make sure your are comfortable with where your data is stored besides the Mac. You can use Time Machine, iCloud, or an external hard drive. See this article How to back up your Mac - Official Apple Support
  2. Go to System Preferences, and then Apple ID / iCloud. Turn off Find My Mac, then sign out of your Apple ID.
  3. Restart the Mac, then when you hear the startup chime, or the screen lights up, immediately press and hold Option + Command + R. Option + Command + R will give you the latest and greatest macOS that your Mac can support. 
  4. Once you are in macOS Recovery, verify you are connected to a WiFi network in the top right corner, and verify your are in macOS Recovery mode you want, such as Big Sur or Catalina. You can tell by clicking on the "Install macOS" app. Once you know what version you have, quit the Installer.
  5. Then go to Disk Utility.
  6. Click the “View” button in the top and select “Show All Devices.”
  7. Select the main hard drive name, not your volumes. For example, select APPLE HDD, APPLE SSD, or Fusion Drive instead of “Macintosh HD.”
  8. Click erase, and input the following EXACTLY:


Name: Macintosh HD

Format: APFS

Scheme: GUID Partition Map


Click Erase


Now, let's reinstall macOS.

  1. Quit Disk Utility.
  2. Open the macOS Big Sur Installer.
  3. Follow the on-screen instructions and select Macintosh HD as your disk to install to.
  4. Let the process finish, don’t restart, sleep, or shut down your Mac. Also don’t disconnect from WiFi.
  5. Let the process finish. Since it sounds like you are trading in your Mac, you don't need to restore data.


I hope this helps!


Cheers,


Jack


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3 replies
Question marked as Top-ranking reply
User profile for user: Jack-19
Jack-19
User level: Level 8
46,002 points

Jan 24, 2021 5:53 AM in response to Ziphoid

Hi Ziphoid,


What ekorko said is correct, but here is my guide for further information to erase your Mac and reinstall macOS:


  1. Backup all DATA! When you do this, all your data will be erased! This action cannot be undone! Make sure your are comfortable with where your data is stored besides the Mac. You can use Time Machine, iCloud, or an external hard drive. See this article How to back up your Mac - Official Apple Support
  2. Go to System Preferences, and then Apple ID / iCloud. Turn off Find My Mac, then sign out of your Apple ID.
  3. Restart the Mac, then when you hear the startup chime, or the screen lights up, immediately press and hold Option + Command + R. Option + Command + R will give you the latest and greatest macOS that your Mac can support. 
  4. Once you are in macOS Recovery, verify you are connected to a WiFi network in the top right corner, and verify your are in macOS Recovery mode you want, such as Big Sur or Catalina. You can tell by clicking on the "Install macOS" app. Once you know what version you have, quit the Installer.
  5. Then go to Disk Utility.
  6. Click the “View” button in the top and select “Show All Devices.”
  7. Select the main hard drive name, not your volumes. For example, select APPLE HDD, APPLE SSD, or Fusion Drive instead of “Macintosh HD.”
  8. Click erase, and input the following EXACTLY:


Name: Macintosh HD

Format: APFS

Scheme: GUID Partition Map


Click Erase


Now, let's reinstall macOS.

  1. Quit Disk Utility.
  2. Open the macOS Big Sur Installer.
  3. Follow the on-screen instructions and select Macintosh HD as your disk to install to.
  4. Let the process finish, don’t restart, sleep, or shut down your Mac. Also don’t disconnect from WiFi.
  5. Let the process finish. Since it sounds like you are trading in your Mac, you don't need to restore data.


I hope this helps!


Cheers,


Jack


Reply

Help with new iMac Please

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