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My disk is formatted with Mac OS Extended (Journaled, Encrypted). I have a super long and random password. It won't let me paste my password in and I keep manually typing it wrong. There is nothing on this disk and I just need to changed the password to something that I can manually change. What do I do? Here is my dialog that I keep getting:

disk unlock password message

Anyone with any suggestions?

UPDATE: I do not care if I lose the data or not.

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Please clarify, do you know the password and this is about entering it correctly, or do you not know it an this is about explaining how forgetting encryption passwords is bad? – Daniel Beck Jan 22 '13 at 6:22
I do not know the password. I do not care if I lose the data. – Jason Silberman Jan 23 '13 at 2:22
Interesting. Usually you'd do this via Disk Utility, but it doesn't allow to partition locked (i.e. encrypted and not mounted) disks. Does this work? – Daniel Beck Jan 23 '13 at 6:42
up vote 3 down vote accepted

Good encryption allows for no recovery. That's how it protects your system from other people.

Encryption sounds like a good idea till you learn to live with it and take extra precautions to prevent the data loss it will force upon you in the event you lose the password. Upon covering all the bases it becomes a useful tool to prevent recovery of data from stolen equipment and not a liability from forgetting the password.

Various other operating systems allow for making a recovery disk or thumb drive when you first encrypt the disk that you can then store in a safe place in case this event happens.

The only recourse is to get it right at least once if you have it written down correctly.

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Not a solution for this question, but you're probably right. If the password is stored in the keychain, OSX allows for an admin password that can open the keychain as well. You can loose both of course. I recommend using a simple and easy to remember password for disk encryption, that others cannot guess easily. Why do you use this? To protect from the NSA or to protect from a friend or thief? In the latter two cases, a simple password will be sufficient. – SPRBRN Sep 10 '13 at 14:15
At the time I answered this little addendum wasn't there UPDATE: I do not care if I lose the data or not. The only solution is to wipe the disk which requires dropping down to OS level utilities to bypass the encryption checks or by mounting it under another OS. See @mpoisot's answer for that. – Fiasco Labs Sep 22 '13 at 18:15

I'm facing the exact same issue. The HD in my MacMini has become corrupted and my only option is to erase it, but, in a fit of security consciousness, I encrypted it with FileVault and so Disk Utility won't erase it at all.

So, not caring about the data on that MacMini (it's just my TV server, nothing that cant be reinstalled and all the actual data is on an external drive) I've booted it in target disk mode (hold down t when you start it up and connect it via FireWire to another Mac) then fire up your Terminal.

% diskutil cs list to get the the Logical Volume Group ID

You want the Logical Volume Group ID

then run

% diskutil cs delete XXXXXXXXXXXXXXXXXXXXXXXXXXXX <-- put the Logical Volume Group ID in place of the Xs

In my case it said

The Core Storage Logical Volume Group UUID is 48AE3F70-916B-4BEB-AF63-0C2423E1481E
Started CoreStorage operation
Ejecting Logical Volumes
Destroying Logical Volume Group
Error: -69783: Unable to delete the CoreStorage Logical Volume Group

You can safely ignore the error however. When I then fired up Disk Utility there was my disk - newly erased. I will now reboot my iMac in Recovery Disk mode and re-install Mavericks on the MacMini. (Fingers crossed)

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Hi, just to clarify, Disk Utility/disktutil won't let you erase a disk encrypted with FileVault? – Louis Sep 20 '14 at 6:00
That's correct. – Dave Sag Sep 20 '14 at 21:45
Did you underline the right volume ID in the screenshot? – qerub Jan 6 '15 at 12:13

Without the current password, you will have to erase and reformat the disk in Apple's Disk Utility. It is always a good idea to store these passwords in a safe place. Apple also allows you to store the key with them. See this article for more information.

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I have tried that, but it will not let me re-format the disk or erase the data. All the tabs in Disk Utility are greyed out – Jason Silberman Jan 23 '13 at 2:25

I started getting this dialog last week. Not sure why the dialog showed up since the disk is still mounted properly.

(I didn't remember the password for this disk so bumped into this question.)

In my case the password is still stored in my Keychain and it's possible to show the password there. Check the "Show password" box (shown in the screenshot below) and enter your administrator password. This allowed me to add it to my password manager.

enter image description here

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I had the same problem, and This SuperUser answer worked. Basically you get into the terminal and use diskutil directly to bypass DiskUtility's overprotection.

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You should provide the relevant information from the answer or just mark this question a duplicate of that one. – Ramhound Apr 23 at 12:19

The only option is to securely erase the effected partition using a similar method to how you encrypted it originally.

You may find this article from OSXDaily helpful.

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Can you please summarize the main points from the article here? – slhck Jun 27 '14 at 17:16

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