Mac – How To Change Time Machine Password – Mac OS Extended (Journaled, Encrypted)

backupdisk-utilityencryptionhard drivetime-machine

How may a Solid-state drive (SSD) Time Machine backup password be changed for a SSD formatted as "Mac OS Extended (Journaled, Encrypted)"?

Expected

This is how a Time Machine backup password is changed for an SSD formatted as "APFS (Case-sensitive, Encrypted)".

APFS (Case-sensitive, Encrypted)

Open Disk Utility app > Select the drive under the External category.
Select in the menu bar File > Change Password…

APFS Volume

Observed

The Mac OS Extended (Journaled, Encrypted) formatted SSD has the option for Change Password… grayed out.

Mac OS Extended (Journaled, Encrypted)

Best Answer

Remove and Re-Enable the Backup Drive from Time Machine With New Password

Open System Preferences > Time Machine
Remove current disk: Select Disk... > Under Backup Disks, choose the existing drive > Remove Disk

Re-enable disk without the existing password: Select Backup Disk... > Select disk > Deselect Encrypt backups > Use Disk

Cancel the disk backup in-progress > Wait for the disk to decrypt
Repeat Step 2.
Re-enable disk with a new password: Select Backup Disk... > Select disk > Select Encrypt backups > Use Disk

Related Solutions

Mac – Why is the “Encrypt backups” option greyed out for local (USB) time machine disc

Make sure that your partition scheme is GUID, not Master Boot Record (MBR) or Apple Partition Map.

To enable encryption, the partition map must be changed to GUID. Note that this will make your drive invisible to older PCs and will wipe all of the data on the drive.

Mac – Reformat a Partitioned Mac OS Extended External Disk

This is an example of a procedure to erase an external disk containing a single encrypted partition.

Open the Disk Utility application and highlight the "Logical Volume Group" representing your external disk. An example is shown below. (Hint: click on image for a better view.)
Next, click the Info icon to get the pop up window. Note, in the example shown below, the "Physical Backing" is disk1s2. This means the physical disk number is 1. The "s2" suffix can be ignored. Your numbers may be different.
Next, highlight the "Encrypted Logical Partition" as shown in the example below.
Again, click the Info icon to get a pop up window. Note the "Disk Identifier". In the example shown below, the value is disk2. Your value may be different.
Close the Disk Utility and open the Terminal application. Enter the following commands. If your numbers differed from mine, make the appropriate substitutions. If prompted, enter your login password.
```
diskutil  unmountDisk  /dev/disk2
sudo  gpt  destroy  /dev/disk1
sudo  gpt  create  -f  /dev/disk1
```
When I entered these commands, I saw the following in the Terminal window.
```
Steelhead:~ davidanderson$ diskutil  unmountDisk  /dev/disk2
Unmount of all volumes on disk2 was successful
Steelhead:~ davidanderson$ sudo  gpt  destroy  /dev/disk1
Password:
Steelhead:~ davidanderson$ sudo  gpt  create  -f  /dev/disk1
Steelhead:~ davidanderson$ 
```
The distutil command must successfully unmount the disk in order for the gpt commands to work. If the disk will not unmount, then some window needs to be closed. Do not proceed with the gpt commands, if you can not unmount the disk.
If successful, you should see a result similar to what is shown below. The result shown is a 4GB flash drive with no partitions. You can either add a partition or repartition the entire drive.