No Time Machine with Encrypted HD

[galvinize]

2017 MacBook Pro, OS 10.13.6

Last year I encrypted my Time Machine external HD because it was going to be mailed and put in storage. When I got it back, I found Time Machine did not work (entering Time Machine revealed there were no backups indicated on the timeline, and there had been many). An Apple Support search confirmed that an encrypted HD cannot be used for Time Machine backups.

My question: can the Time Machine function (with items saved before the encryption) be restored by un-encrypting the HD?

 

[MacInWin]

Wouldn't hurt to try.

 

[Raz0rEdge]

Assuming you un-encrypting the HD will return the contents to how they are normally, then Time Machine should be able to see things no problem. Did you use macOS to encrypt the drive or a 3rd party tool?

 

[IWT]

This article might help.

How to Encrypt Your Mac’s Time Machine Backup

From what I read there and here (Keep your Time Machine backup disk for Mac secure - Apple Support), the process of setting up a Time Machine Backup (BU) is the critical phase.

That said, the implication of both articles is that it is possible to do and possible to unencrypt TM and recover your data.

Never done it myself, but worth a read, I think.

Ian

 

[galvinize]

Thanks for all the replies!

As I recall, I encrypted the HD with Disk Utility, and will see if un-encrypting the HD restores Time Machine.

 

[galvinize]

An update on this post: I connected the external drive and "right-clicked" the drive icon, then clicked "decrypt drive". Now the window says "Decrypting Drive" and is greyed-out. Does this indicate the drive is in the lengthly process of decrypting? Time Machine still does not recognize backups in this drive.

 

[ferrarr]

Yes, the drive is decrypting. Depending on the size (GB) of the drive, it could take days to complete. This is especially true, if there is data on the drive.

 

[MacInWin]

And do not interrupt the process until it is complete or you stand a fairly good chance of losing it all.

 

[galvinize]

Well, I may have lost it all, because the laptop went into sleep mode while the HD was decrypting! Will soon see if this occurred.

 

[MacInWin]

Sleep may not have done anything bad. Sleeping generally includes soft shutdowns so that things can be restarted when it wakens. You could still be good!

 

[galvinize]

That's good news! Is there any way to monitor the decrypting progress?
Also, is there a way to encrypt and still use Time Machine?

 

[MacInWin]

Well, you could open Activity Monitor (In the Utilities folder of Applications) and see if there is disk activity, or what is using CPU. That's about all I can suggest.

 

[galvinize]

Thanks! Looking at Activity Monitor:

kernel_task 7.5% CPU; CPU Time 1:31:06 and counting; threads 149; idle Wake Ups 626

 

[MacInWin]

kernel_task is a catch-all for a lot of things. Anything going on in the disk activity pane?

 

[galvinize]

Browsed through the web and found this suggestion:
go to the Terminal App in Utilities and type: diskutil cs list
Sure enough, it revealed the decryption was 41% complete.

 

[galvinize]

A final postscript to this thread: The external drive is now decrypted (a 24 hour process for the 400 GB content!), but it still does not show any Time Machine backups on the right-hand vertical timeline. The backed-up material is there in dated folders, but any recovered data must be retrieved manually. So it appears one cannot encrypt an existing Time Machine drive, but a new drive may be encrypted before being used for TM>

 

[ferrarr]

The proper way to encrypt Time Machine s witting the Time Machine control panel.

Keep your Time Machine backup disk for Mac secure - Apple Support

 

[galvinize]

Another postscript for the archives of what-can-go-wrong.

Once I determined that decrypting my external HD would not restore its Time Machine capacity, I re-encrypted the drive. It took three days. And now, the "Enter password" window is very slow to appear, slow to respond, and many folders are "aliases" (when opened, the message appears: "The alias "Desktop" can't be opened because the original item can't be found").

I don't believe these aliases were present before the re-crypting. Ran Disk Utility, and got a long list of "error: Underallocation Detected on Main Device". I thing it's fair to conclude the HD is toast... perhaps due to due to the decrypting/re-encrypting?

 

[MacInWin]

Did you run DU on the hardware itself? That's the higher level, not indented, item in DU. It looks to me like the multiple attempts to encrypt/decrypt the drive has mucked up the directory structure, which would be fixed by reformatting, but no point in doing that if DU reports problems with the hardware.

 

[Rod]

Thats a handy thing to know. TM task progress (or the lack of it) has always been a bit of a sore point for me. When a task takes this long it's pretty valuable to know where it's at and indeed if it's doing anything at all.