OS Monterey doesn't have the option to make an external ssd bootable

Luise wrote:

I have OS Monterey and I am trying to make an external SSD bootable, but there is no option for that in disk utility, how can I fix that

No.

Use Carbon Copy Cloner.

Mac Backup Software | Carbon Copy Cloner | Bombich Software

About Startup Security Utility on a Mac with the Apple T2 ...

Startup Disk security policy control for a Mac with Apple silicon

i needed a catalina boot drive. i followed the instructions in this informative user tip: How to Setup and Use an External SSD as your Startup Disk - User Tip.

although i did things a little different. first, my mac shipped with catalina, so when i booted into recovery, i used the "shift-option-command-R" keyboard combination to be able to download and install catalina on the external SSD. here are a couple other recovery options you can try: How to reinstall macOS

and also, i still use my internal drive with monterey for my day to day. whenever i need to use catalina, i press and hold the "option" key on startup until i see the option to choose which drive i want to boot into.

Luise wrote:

I have OS Monterey and I am trying to make an external SSD bootable, but there is no option for that in disk utility, how can I fix that

If in doubt you can read more:

https://bombich.com/kb/ccc6/cloning-macos-system-volumes-apple-software-restore

"It is my understanding that MacOS Monterey will no longer support bootable external drives."

Not true, I can boot form my external drive, no issues. The issue is that Carbon Copy cloner is currently unable to create a bootable drive.

The work around is to install the latest version of macOS on your external drive and internal drive, then use CCC to backup the internal to the external. The external will be bootable.

The trick is that you need to keep the external drive's macOS version up to date by installing them while booted to the external before attempting your backup. CCC's can't clone a 12.2 volume to a 12.1 volume without making the 12.1 volume unbootable in the process. The extra step is that you have update the macOS version on the external before doing your backup.

It is my understanding that MacOS Monterey will no longer support bootable external drives. I discovered this the hard way. I am a Carbon Copy Cloner user and have cheerfully been backing up every night. I went to use the CCC disc and discovered that it is not recognized as a "target disc."

The bombich website says essentially the same thing.

https://bombich.com/kb/ccc6/cloning-macos-system-volumes-apple-software-restore

In part,

'Copying Apple's system is now an Apple-proprietary endeavor; we can only offer "best effort" support for making an external bootable device on macOS Big Sur (and later OSes). We also do not generally recommend that users attempt to make their backups bootable'

I would like to know if anybody out there has dug into this and has come up with a workable solution. I presume I am preaching to the choir, but not having a bootable clone is a *disaster.* Most obviously, if my internal drive fails, I can no longer just keep working.

How are all you "work from homers" dealing with this?

MacOS Monterey 12.1

2017 27" iMac 3.5 GHz Quad-Core Intel Core i5

No, Carbon Copy Cloner is able to create bootable external SSDs with version 6.

You need to use their Legacy Backup Assistant feature:

Per this it can be done:

https://forums.macrumors.com/threads/carbon-copy-cloner-6-monterey-bootable-backup.2332092/

Thanks, I'll give that a try next time, but it only appears to work because it completely erases your backup drive first.