PERockwell

I'm working in audio so have large drives to back up and external data drives.   Time Machine shows internal drives and partitions but my data is on the external drives.  Will Time Machine backup those too, but that would mean I need like a crazy expensive 8TB SSD.

Time Machine will back up external drives - just ensure that they're not excluded.

As far as backup storage goes, don't rule out large capacity external HDDs formatted with APFS for TIme Machine storage. The performance characteristics of Time Machine backups don't stress the performance available from HDDs (one of the few good use cases for APFS formatted HDDs). 

sflagel said:

Does Time Machine only back up the user that is currently logged in, or all users of the device being backed-up? As much as I would love my family to back up their stuff, they won't. And we use many different devices and mix and match. Also, does anyone know the best solution to back up a MacBook Air to a network / wirelessly connected drive? I would love not to have to plug in an external drive regularly.

Time Machine will back up everything on your Mac (for all users) with the exception of the operating system itself (the read-only snapshot that the core macOS boots from) and any files/folders/volumes that you have excluded from backup. 

There are several NAS vendors that provide networked storage that can be used for Time Machine backups over the network. In addition, if you have a "stationary" Mac, you can configure storage as a destination for another Mac's backup over the network.

I knew that the fictional Lumon Terminal Pro looked familiar.  It’s a rip-off of the mid-1970s Data General Dasher D2/D3 CRT:
https://terminals-wiki.org/wiki/index.php/Data_General_6053

andbu said:

FYI , I don’t any update. Still running 15.2  (24C101)

You already have the update that fixes this issue. It was addressed in Sequoia 15.2 (released, not coincidentally, on 11-Dec-2024), per Apple's article https://support.apple.com/en-us/121839

pdxGuy1959 said:

Mike Bombich updated his older post, as of 12/19, with a new Blog comment on this topic...

https://bombich.com/blog/2024/12/19/bootable-backups-have-been-deprecated-for-several-years

An interesting update from Mike Bombich which adds more context to why Apple moved away from use of ASR to copy the operating system for a bootable backup. 

My feeling after reading what Mike has written is that this "bug" may not be considered a "bug" by Apple.