Invisible Disk Encryption Password Request (Possible bug?)

[bluelizard]

I installed 3.6 with LVM and encryption enabled for the whole hard drive. When I boot, I see just the feather splash screen. I can type in my encryption password and it boots normally, but there is nothing on the screen asking for the password. If it doesn't fully boot, I can't tell if it's hanging or I just typed the password in wrong.

The only related post I've found had a user installing 3.4 multiple times due to "hanging" issued until it worked correctly: https://www.freecinema2022.gq/forums/start.../#msg33720
I'm wondering if this user was encountering the same problem but hadn't tried typing in their password when it seemed to hang.

Is there something I'm missing here? If it is a bug, is there a verbose mode I can switch on for boot if the password request is showing up as text underneath the splash screen?

[Scott(0)]

8)

Hi Bluelizard


I don't use lvm/luks (disk encryption) but I'm going to try to help. If I Google the phrase ubuntu 16.04 lvm luks password prompt I get lots of results that look like they could help. Here's the first one, for example.


[SOLVED] No LUKS password prompt for Ubuntu installation with manual partitioning
https://ubuntuforums.org/showthread.php?t=2353595


Scott

[bluelizard]

8)

I don't use lvm/luks (disk encryption) but I'm going to try to help. If I Google the phrase ubuntu 16.04 lvm luks password prompt I get lots of results that look like they could help.

I didn't find a direct solution, but it gave me the hint I needed to figure this out. LUKS is working fine, but Plymouth is covering the password prompt. Once the password is entered, it displays "Cryptsetup: (drivename) set up successfully" on top of the background, but it's hard to see with the default splash background. I tried making the background transparent, setting the background colors to 0 (black/transparent) in Plymouth's config file and updating initramfs, but the prompt is still not visible. I'm not sure if Plymouth is covering the prompt or pushing it off the screen.

What does work is shutting off the splash screen in GRUB.

Open a terminal window, then open etc/default/grub in leafpad as root:

Code:

sudo leafpad /etc/default/grub

Find this line:

Code:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Remove "splash." "quiet" can be left in.

Code:

GRUB_CMDLINE_LINUX_DEFAULT="quiet"

Save the file and close Leafpad. Update GRUB:

Code:

sudo update-grub2

Now it will boot without the splash screen and the LUKS password prompt shows up as plain text. Enter the password, and it continues booting normally.

[trinidad]

There are separate sprites you can configure for this in the plymouth Liteboot script. The sprite for the password must have a higher Set z number than the background sprite and the logo sprite both, or any other sprites.

Not a bug. Just something in Ubuntu that cannot be auto-configured.

TC

[bluelizard]

There are separate sprites you can configure for this in the plymouth Liteboot script. The sprite for the password must have a higher Set z number than the background sprite and the logo sprite both, or any other sprites.

I tried changing the settings so everything outside of the password and dialogs has a low Z setting, but it doesn't seem to work. I also can't figure out why the password entry would be hidden, but the dialog once the password has been entered shows up. I'm going to leave this as "Solved" since shutting off the splash screen works and leave it up to someone with better Script-Fu to get Plymouth working with LUKS.

[trinidad]

Get back to you. Not on LL right now.

There is a bug but only with some nvidia drivers.

Did you happen to have one successful boot where the password prompt was displayed in plymouth, and then on the next boot quit working? 

TC

[bonnevie]

I'm a bit late to this conversation, but the same thing is happening with my Intel SSD setup. The solution for me is simply to hit Esc, which makes the splash screen disappear, unhiding LUSK verbose.

[bluelizard]

Did you happen to have one successful boot where the password prompt was displayed in plymouth, and then on the next boot quit working? 

TC

No. It never worked.

I'm a bit late to this conversation, but the same thing is happening with my Intel SSD setup. The solution for me is simply to hit Esc, which makes the splash screen disappear, unhiding LUSK verbose.

I tried this with and without "quiet" in GRUB's boot options, and it just shows a blank screen.

[ian_r_h]

Also chipping in rather late after modem issues earlier.

I have whole disk encryption on my old Acer laptop (my test unit) and my two main LL units (bespoke hardware).  Each unit has the same invisible passphrase prompt feature - but entering the password poses no additional problem (except as said above the confirmation of encryption setup is hard to read white on yellow).  Each unit is, I think, Intel graphics - and it happens on the internal monitor and/or external (Acer) ones.

Just confirming the "feature", as I don't consider it serious enough to suggest it as a bug as such.

But it might be useful to add it to the manual in future, as it is confusing for us newbies when first encountered! 

[Valtam]

We're likely to go with a black background boot splash in Series 4.x

This should help people with disk encryption see things more clearly.