I want to know where the working tutorial for installing Catalina on an external drive is.

All the tutorial I managed to google up for some reason failed to mention the "missing a firmware partition" error.

I tried to install it using clover or raw official installer, under a GUID scheme. All got stuck at this "firmware partition" gag. I tried to use apple FS but to no avail.

Would someone please help me? This is driving me nuts. My MacBook is genuine, not HacBook.

  • This is likely to be closed re: Finding an off site resource. However, this is not a difficult prospect as installing on an external drive is no different than installing on an internal drive. I would be willing to work with you to write a proper guide - get in contact with me via my profile and lets see what we can do. – Allan Jul 30 '20 at 0:35
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    As for where you got stuck, the description "firmware partition gag" doesn't really help. Also, it's not clear as to why you're using clover. This is where a lot of confusion comes in. – Allan Jul 30 '20 at 0:37
  • The tutorial is as simple as the answer you got below. To resolve the "missing a firmware partition" issue, please ask a new question describing the problem in more detail. – nohillside Jul 30 '20 at 7:07
  1. Plug the external drive to your MacBook and Launch Disk Utility.

  2. Select the external drive on the left-hand side panel, select Edit>Erase, choose APFS and GUID partition map and press Erase:

    enter image description here

  3. Download Catalina installer from your genuine MacBook App Store by clicking this link.

  4. After downloading, the installer launches automatically. If you want to install Catalina at a later time, you can find the installer in the Applications folder:

    enter image description here

  5. Follow the onscreen instructions, and when asked where to install Catalina, choose the external disk.

  6. You MacBook will restart and proceed with the installation.

When the installation is over, to boot from the external disk, start up your Mac and press and hold the Option key to display the Startup Manager. Choose the external disk and click the arrow under its icon.

See these support articles about installing Catalina and erasing a disk for more information.

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    The only thing that might be missing is use disk utility to erase the external drive. Choose all defaults when erasing. – bmike Jul 30 '20 at 1:10
  • Didn't work. "Target device missing a firmware partition" etc. etc. – cream_pi Jul 30 '20 at 2:40
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    @cream_pi I've expanded bmike's answer with information on how to erase the external drive first, could you give it a try? (@bmike: took your comment literally and added the missing bit about Disk Utility, hope it's OK) – jaume Aug 6 '20 at 14:55
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    Such a large improvement in quality and usability. Thank you kindly @jaume I generally format externals HFS+ but your example is not wrong, (and may get converted at install time). I find it less error prone to let the installer convert and have zero containers. – bmike Aug 6 '20 at 21:43
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    @bmike Thanks :-) Yes, HFS+ is probably the way to go for USB drives, but since the OP wants to install Catalina, I thought APFS may better. Anyway, the installer makes the final decision and chooses which format is more appropriate. – jaume Aug 9 '20 at 16:07

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