Cloning Time Machine drive?

[derekw]

Am I right that SD! cannot clone a Time Machine backup drive?

The reason I may want to do that is as follows. I have an M1 Mac running Monterey which I back up to an external HDD APSF disk using Time Machine. I expect if my Mac dies suddenly, I would get a new Mac and restore from the Time Machine backup. But during the time after the Mac dies and before the restore is successful, my one and only copy of everything is the Time Machine drive. I thought I should immediately clone the Time Machine drive to another drive before using it for restoring, just in case anything goes wrong and damage the TM backup. Is it possible to clone a Time Machine drive?

If cloning is not possible, I guess I could first restore the latest snapshot onto another external drive as an extra backup and if I somehow damage the Time Machine drive, at least I still have the latest version of my stuff on another drive. But then this step also has the potential to somehow damage my Time Machine drive.

[dnanian]

No, you are wrong - we can. But we can't copy an APFS Time Machine drive. Please see this FAQ:

https://shirt-pocket.com/forums/showthread.php?t=3565

[derekw]

Thanks, Dave. So in order to clone a TM drive, both drives must be formatted with Mac OS Extended (Journaled). If one or both drives are APFS then cloning cannot be done.

I don't think I would change my TM backup to Mac OS Extended (Journaled) just for this purpose. Seems like for my use case as described above, there's no easy and risk free way to make a duplicate of my TM drive before proceeding with the restore process.