Level 1

99 points

Can't install macOS 15.4 on external volume

I am trying to install macOS Sequoia 15.4 on an external volume. The external volume is on an external drive and shares space with another volume. The drive is formatted APFS, GUI Partition Map and is connected to my Mac by USB 3 compliant USB "B" to "A" and USB "A" to "C" adapter. It is plugged into a Thunderbolt 4 port on the back of my Mac. My Mac is running 15.4.

I have tried various ideas but get the same end result:

the install is completed – it does a restart so I think it's complete;
the volume is locked;
the volume cannot be booted; and
so, the install process did not boot and enable a user account to be created.

I cannot find an installer log.

When the locked volume set as Startup Disk, there is an error "The version of macOS on the selected disk needs to be reinstalled.". When I try to run the installer again get another error: "This volume cannot be used since it has a secure token without any users. Please use Disk Utility to erase this volume.".

Things tried:

run installer from standard user account;
run installer from admin user account;
run installer from Recovery;
reduced startup security – have learned that is NOT necessary despite some Mac magazine articles;
toggled "Copy account settings from ....";
changed name of the Volume – took out space characters;
made sure the drive is NOT plugged into the DFU port.

Is installing on external volumes no longer possible ?

Mac Studio, macOS 15.4

Posted on Apr 8, 2025 9:35 PM

Top-ranking reply

Kennyuc99

Level 1

14 points

Posted on Apr 10, 2025 12:11 PM

Sequoia 15.4 tiene problemas para ser instalada desde 0.

Es la versión y el instalador de Sequoia lo que falla, no la forma en que formateas el disco.

Incluso en las MacBooks o equipos con M1 falla el instalador, dejando los equipos sin sistema, aparece exactamente el mismo mensaje que te aparece a ti de terminar la instalación.

Yo no puedo instalar MacOS desde el recovery o una USB booteable.

Solo queda esperar que se solucione por parte de Apple, no sé si en otra versión o en esta, lo que sí podrás hacer es instalar una versión inferior a Sequoia 15.4

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27 replies

Owl-53

Level 10

102,385 points

Apr 9, 2025 3:30 AM in response to Ian R. Brown

Ian R. Brown wrote:

Your suggestion to create another volume rather than partition has an extra advantage.

A partition is fixed in size which later on you might find to be either too big or too small whereas the extra volume is flexible and will stretch or shrink to accommodate what you put in or remove. (At least that was my understanding! 🫢)

You are very correct

APFS Volumes over partitions which Lock things in

Garry Brooke Author

Level 1

99 points

Apr 9, 2025 5:58 PM in response to Owl-53

It's a need to. I'm a developer and I am trying to replicate an issue with my applet experienced by a user who is currently booting from an external drive. Otherwise, I have sufficient backup facilities. Your comment about Apple Silicon needing a functional internal drive is correct. The macOS installer will only enable installation on an external drive if there is a functioning admin account on the internal drive. Yes, next I will try to install on an entire drive. I'll also test installing on a fixed size partition.

Garry Brooke Author

Level 1

99 points

Apr 9, 2025 10:39 PM in response to Garry Brooke

UPDATE: Tried to install on a partition on an external drive – failed in same way as before. The partition was in a separate container and so did not share space with the other volume. Will now try to install on an external drive with one container of one volume.

Garry Brooke Author

Level 1

99 points

Apr 10, 2025 3:55 AM in response to Ian R. Brown

Yes, that's my thought at present – I downloaded it from the App Store. A friend has another copy which has a different version, 20.3.04. I have been using version 20.4.02. I assume that there are changes which justify a different version number.

Garry Brooke Author

Level 1

99 points

Apr 11, 2025 9:28 PM in response to HWTech

Thanks. I did check that I was not using the DFU port. I chose an admin account during every install attempt. I had to enter the password for that account twice each time no matter how I invoked the installer. Don't think it's so bad I need to do a DFU revive or restore.

Apr 9, 2025 12:45 AM in response to Garry Brooke

See other discussions related to Sequoia installation, recovery or update.

Garry Brooke Author

Level 1

99 points

Apr 9, 2025 6:05 PM in response to Ian R. Brown

Thanks for the link to the video. As mentioned, the entire drive is formatted GUID Partition Map.

Apr 10, 2025 12:32 AM in response to Garry Brooke

Did you watch the first couple of minutes detailing formatting in the video I posted?

Follow it step by step.

It may be boring but boring usually gets the job done.

Apr 10, 2025 4:09 AM in response to Garry Brooke

My version is 20.4.02 and has worked OK on both the internal SSD and the external.

I always keep a copy because you never know when you will need it again and it cuts out the hassle of downloading.

Garry Brooke Author

Level 1

99 points

Apr 10, 2025 4:44 PM in response to Ian R. Brown

Ian, thanks. Yes, I did look at the video and I did format the entire drive in one experiment. Every time, I check that the entire drive is formatted GUI Partition Map. Cheers.

Garry Brooke Author

Level 1

99 points

Apr 12, 2025 6:01 PM in response to LuizAlvarez

Much the same happened to a friend recently trying to update a 15.3.2 install to 15.4 on an internal SSD. Lots and lots of errors and trouble.

s437885

Level 1

14 points

Apr 13, 2025 4:57 PM in response to LuizAlvarez

Same. Update borked my external boot setup.

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Can't install macOS 15.4 on external volume