Confused by Catalina

[louabill]

I have a Catalina-laden laptop with FileVault turned on. I would like to back it up to an encrypted external drive volume [1] whose last backup was made under Mojave.

I tried a smart update, and I got the (expected) error message:

The easiest thing to do is to use "Erase bill_backup, then copy" as your During copy method in Options. Once the copy is complete, you can start up from the backup, turn on FileVault, and future encrypted Smart Updates will work as expected.

Does this message imply that I need to have FileVault turned off on the laptop before backing up?

This would make the backup steps:

1. Decrypt laptop
2. Wait for FileVault to decrypt internal volume
3. Backup laptop using "Erase ... then copy"
4. Boot off backup
5. Turn on FileVault
6. Wait for FileVault to encrypt external volume
7. Boot off laptop
8. Turn on FileVault
9. Wait for FileVault to encrypt external volumen
10. Check that backup works without hassle

Is this correct, or am I making things too complicated (and waaaay to long for a 1TB drive backing up to old spinning hard drives)?

Thanks for any clarification, shortcuts, or other tips.

Bill
[1] I say 'volume' because the external drive is an apfs drive with multiple volumes.

[dnanian]

You're making it more complicated. This is just relevant to the BACKUP drive. So, as it says, just erase, then copy. Then start up from the backup, turn on FileVault, and boot back. You don't have to wait for it to finish.

[louabill]

Thanks for the quick answer. So... the proper procedure would then be

1. Backup laptop using "Erase ... then copy"
2. Boot off backup
3. Turn on FileVault
4. Shut down
5. Boot off laptop
6. Check that backup works without hassle

This is indeed much simpler.

I'm posting this so that there is a place I'll find it the next time I get confused. Happens all the time.

Thanks again.

[dnanian]

You don't have to shut down. Just use the startup disk preference pane to boot back to the laptop.