You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

How to un-encrypt my Time Machine back up disk

I have an external USB hard drive that I back up to using Time Machine. I've been using the disk for years. I've just noticed in the Time Machine preferences that it says the disk is 'encrypted'. I presume this means that I must have set up a password for the disk so that if someone plugs the disk into a different computer they can not access my files without the password?


Trouble is I can't remember what the password is.


How do I un-encrypt my disk / TM backups?


Do I have to use Disk Utilities to wipe the disk clean and then resume TM? That could take hours...

MacBook Pro 15″, macOS 11.2

Posted on Jun 7, 2021 2:11 AM

Reply
Question marked as Top-ranking reply

Posted on Jun 7, 2021 6:13 AM

As stated - without the password there is nothing that can be done. To reclaim the space and repurpose the Entire Drive requires a Re-Format as suggested. If you what to leave the space Occupied - leave it alone and create a new APFS Volume on the drive for a New TM Backup.

Similar questions

5 replies

Jun 7, 2021 4:48 AM in response to Sparky Marky

Will concede to more Learned Contributor on this one - but think without the password to decrypt the drive - the only option is to Wipe the Entire Drive in Disk Utilities. When Wiping the Drive in DU >> View >> View ALL devices and choose the Upper Most name of the Drive to wipe and then choose Erase and format to desired format ( APFS for repurposed TM Backup or HFS Journaled for general usage ) both with the GUID Partition Map.

Jun 7, 2021 5:48 AM in response to woodmeister50

FWIW, if there was a way around using a password to decrypt
a disk, it would make encrypting it pretty useless.

Your only option, reformat the drive and start TM all over.


I get that, but on my Mac I have never been asked for the password, so I was hoping for a way to un-encrypt the disk without having to reform it and start again... like make future TM backups un-encrypted and leave older backups encrypted?

How to un-encrypt my Time Machine back up disk

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.