Forward: Turn off Filevault on macOS

Turn off Filevault on macOS:
https://kane.mx/posts/2021/turn-off-filevault-on-macosx/
Oct 31, 2021,
Tags: MACOSX, MACOS MONTEREY, FILEVAULT, TIP

I'm trying to upgrade my Macbook Pro to macOS Monterey,
however the installation can not be started due to the disk is encrypted by Filevault 😕
I have to turn off Filevault to disable disk encrpytion before installing macOS Monterey.

I found this support article on how turning off Filevault,
but it does not work at all. There is nothing hint or error message after clicking the option Turn off Filevault.
After researching it for a while, I found this post via CLI command,
$ sudo fdesetup disable

But above command also does not work, it exits with error code -69594 as follow:

$ sudo fdesetup disable
Enter the user name:abael
Enter the password for user 'abael':
FileVault was not disabled (-69594).

I found some articles said that the Filevault only can be disabled by the user whom enables it.
I found below command to show the user whom enabled the Filevault,
it's enabled by an unknown user! I don't have idea how enabling it.

$ sudo fdesetup list -extended
ESCROW  UUID                                                                     TYPE USER
        2D3F7CA5-4ED4-4537-8DA2-98B1E3637954                   Unknown User

Finally I found below command line to disable Filevault though I don't know which user enabled it.

$ diskutil apfs disableFileVault disk1s1
Passphrase for existing "Disk" user C099E506-4FB9-3C91-AB16-3FDCC9BEB01F:
Starting background decryption of disk1s1 using the "Disk" crypto user as authorization
Background decryption is ongoing; see "diskutil apfs list" to see progress
bash-3.2# diskutil apfs list
APFS Container (1 found)
|
+-- Container disk1 FA085B60-3AD2-47EA-B139-66D1A3F67CF2
    ====================================================
    APFS Container Reference:     disk1
    Size (Capacity Ceiling):      250685575168 B (250.7 GB)
    Capacity In Use By Volumes:   217974448128 B (218.0 GB) (87.0% used)
    Capacity Not Allocated:       32711127040 B (32.7 GB) (13.0% free)
    |
...

$ diskutil apfs disableFileVault disk1s1 -user disk

Input the disk password when booting the macOS.
The disabling Filevault will be processed in backgroud, you can retrieve the progress by below command,

$ diskutil apfs list

Happy Monterey!