Bitlocker presence prevents installation despite having free space

Asked by Amin Husni

I am trying to install Ubuntu 23.10.
My primary OS is Windows 11 with Bitlocker enabled.

Installation of Ubuntu was blocked due to Bitlocker being enabled. The setup screen suggests that I go into Windows and create free space to proceed.
However, free space is indeed present.

It seems like it detects Bitlocker is enabled and blocks the installation without checking that free space exists.

One workaround for this is to decrypt the Bitlocker partition, install Ubuntu, then re-encrypt Windows with Bitlocker.
This option is undesirable as it will put a lot of wear and tear into an SSD.

I am wondering if this is a bug or if there are other unseen reasons why the installer should be blocking the installation despite having free space with an active Bitlocker setup?

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Bernard Stafford (bernard010) said (last edit ):

Please open the BIOS F12 or F10 or F2 during startup.
Disable fast boot & secure boot.
Make your USB with Ubuntu first in the boot order.
Save and exit. Have your USB in a slot, computer will restart.
You can turn back on after the install.
Remember to have 25GB of free space or more.

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Amin Husni (aminhusni-5) said :

I've checked, fast boot was disabled. I disabled secure boot.
I have 100GB of unallocated space at the end of my Windows partition.

Still does not work. I think the installer is just detecting Bitlocker is present and blocks the installation regardless.

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Bernard Stafford (bernard010) said :

It could be, if it encrypted the entire hard drive.
It would not find the difference from partition and free space.

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Amin Husni (aminhusni-5) said :

I am absolutely certain it is not encrypting the entire drive.
It is an unallocated space. Bitlocker can't encrypt an unallocated space.
I've even gone into the manual partitioning mode, formatted the unallocated space, and deleted the formatted space into an unallocated space using the Ubuntu installer GUI.

Other people are having the same issue such as this one:

My intent in filing this question here is to find out the reason (and potentially convert to a bug report) why the installer blocks the dual-boot installation when it detects Bitlocker, despite saying you have to allocate some free space and there is indeed free space.

If there is no reason behind the block then it would be a bug in the installer because it seemed to me, that it should first detect if Bitlocker is present, then detect if there are free allocations available to install Ubuntu on. However, the present behavior of the installer is to block the installation when Bitlocker is present without checking if free space is available.

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Manfred Hampl (m-hampl) said :

If you boot the Ubuntu installer in the "Try Ubuntu without installing" mode, what output do you then receive for the command

sudo fdisk -l

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Amin Husni (aminhusni-5) said (last edit ):

I have instead opted to install OpenSUSE and it worked perfectly fine, installing alongside an existing Windows BitLocker partition without having to do any manual partitioning. I needed to get my laptop running dual-boot so I can't provide you the command output after the fact.

I can assure you, that the SSD structure is:
[EFI] [Windows Bitlocker] [Unallocated Space]
This is confirmed in both the Windows partitioning tool and Ubunutu's installer manual partitioning tool.
The unallocated space was repeatedly formatted, unformatted etc. using Ubunutu's own manual partitioning tool in an attempt to diagnose the situation.

If it is worth anything, here is a picture when I was in the manual partitioning mode:

Please note that I've attempted to install using both the new installer and the old installer. They both blocked my installation due to the presence of a Bitlocker partition, despite having free space/unallocated space.

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Casey Jeppesen (cjepp) said :

Did you ever find a solution?

Can you help with this problem?

Provide an answer of your own, or ask Amin Husni for more information if necessary.

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