Is Time Machine broken or is it just me having trouble with 'decryption'?

[Arubalube]

I've been trying to get Time Machine to create an encrypted back up for MONTHS and it won't work—is it just me or is it broken?

I've not seen anyone else with this problem & in the past Time Machine has worked reasonably well. So I'm guessing its some kind of weird interaction with my set up. Has anyone else had these problems? Or do you know what the decryption process is and why it's being invoked here?

I'm running Catlina on a Mac mini (2018 with T2) and the drive is a Western Digital that's connected by USB-C cable, transferring data by the Thunderbolt 3 protocol.

In my most recent failure:

1. Use Disk Utility to format the external drive as 'macOS Extended (Journaled, Encrypted)'. I set the pass for the drive and asked KeyChain to NOT remember the pass, so that I could easily check that the encryption was working later on.
2. Select the option to have Time Machine encrypt the back ups.

• [I appreciate that this is unnecessary, drive OR back-up encryption would be fine but if I did not select for TM BU encryption, Time Machine through an error saying that there was an error preparing TM: the core storage logical volume is already decrypting. So, I started again and elected to have TM encrypt the BUs, in addition to the drive being encrypted].

1. Eliminated the home directory of my Mac from the BU to get it to work fast so that I could check the encryption and perform a full BU afterwards. This performed the back up in a couple of hours. Good.
2. Right after this, and without asking, Time Machine began 'decrypting'.

• Once this started, I got suspicious and looked at the Drive in Finder and About this Mac/Hardware/USB, which thought that the drive was 'macOS Extended (Journaled)'. No mention of the encryption that should have been there. BUT Disk Utility thought that that the drive WAS encrypted, listing ''macOS Extended (Journaled, Encrypted)'.

1. Now—10 days later—Time Machine has finished decrypting.

• Disk Utility thinks that the drive is not encrypted ('macOS Extended (Journaled, Encrypted)'). If I try the drive connected to a different machine, it opens without prompting for a pass and all the BU files are accessible.
• BTW—I confirmed that the pass for the drive was not saved in KeyChain.
• So neither the drive nor the BU encryption has worked. It looks as though TM has been changing the format of the drive and un-encrypting the first pass BU during its 10-day decryption.

 

[palebluedot]

I am having problems with a TM backup on Catalina. My wife sent her Mac in to be repaired, and when we got it back (I Formatted it before sending) it can't read the TC disk - says it is encrypted. I do not remember encrypting it, but don't have the Keychain to see. I tried every password I could think of, no luck. Wonder if it is related?

 

[Fishrrman]

I'd abandon the idea of encryption for a backup drive.

When you "need a backup", the LAST THING you want are more problems trying to "get to the data".

If the data on the backup drive is that important, either lock the drive in a safe or keep it well-hidden.

My opinion only.
Others will disagree.
Some will disagree vehemently.

 

[Marty_Macfly]

I'd abandon the idea of encryption for a backup drive.

When you "need a backup", the LAST THING you want are more problems trying to "get to the data".

If the data on the backup drive is that important, either lock the drive in a safe or keep it well-hidden.

My opinion only.
Others will disagree.
Some will disagree vehemently.

Hi Mr F,



You have answered my next question on setting up this new HDD for mine!

I'm with you on this one. Thanks for the sanity check.

My primary concern for the Mac would be - I'm reading that Time Machine can be flakey with drive not connecting / loosing connection - So my concern would be it keep popping up asking for the Password again, for example as 2am, 4am, 6am for any urgent overnight backups!

Onto the next questions!



Regards
Martin