Chainloading TrueCrypt with GRUB2

[auftable]

For me too! Thx for the instructions! But there is a little problem with the rescue iso: everytime I select my windows partition the truecrypt bootloader gives me the following error:

"it appears you are creating a hidden os. is this correct (y/n)"

If I press "no" the regular boot screen appears and I can enter the passphrase. Does anybody know how to disable the message?

I don't know, but I reported it as a bug to the truecrypt developers.

[derfan]

Hi ;)

I am following this thread since quite a while and would like to thank you for your explanations. For me it was working nicely, except that I would also see the "hidden OS error".

Since a week I reinstalled my system and I am now using TC 7.1 and Ubuntu 11.10. The TC ISO wont boot anymore, memdisk says "Not enough memory to decompress image (need 0xcaf3c002 bytes)". I am not sure if I did something wrong or if it is indeed the new version of tc and/or grub. I did some further research about this but couldn't find anything. Is anyone else having the same problem?

While researching I found this thread:
http://www.linuxquestions.org/questi...lation-877873/
leading to a nice piece of software called grub2tc:
https://gitorious.org/grub2tc/
From the grub2tc README: grub2tc converts the TrueCrypt boot loader into a multiboot kernel that can be loaded from grub2.

Unfortunately this tool didn't work for me either (I still guess its because of the new TC version), but the readme file of the grub2tc project nicely explains the "hidden OS" error along with some other interesting information about the grub and tc mbr.

More from the grub2tc README:
If the TrueCrypt bootloader prints"Error: It appears you are creating a
hidden OS." then some remainders of the TrueCrypt MBR are still sticking
around. You can either ignore this and reply "n", or you can venture into
hacking your MBR to disable this message:
1. Make sure that it really is a TrueCrypt MBR:
dd if=$yourhd count=8 bs=1 skip=6
prints "TrueCryp"
2. Remove the TrueCrypt marker:
echo 'grub<3tc' | dd of=$yourhd count=8 bs=1 seek=6

Cheers,
Benjamin

[rogonow]

I don't have a separated partition as boot. My solution, after very much searching to get an acceptable boot system:
Unmount Windows (like XP) permanently in Ubuntu.
TrueCrypt Windows partition in Windows + make TrueCrypt repair CD.
Repair GRUB with corresponding Ubuntu live CD (LTS 10.04 in my case)

This will launch Ubuntu always when it boots from the hard drive.
For Windows, I use the TrueCrypt repair CD as boot CD. My Windows partition is hidden although I didn't select to make a hidden one. I launch boot menu to select boot device.

I can mount my Windows in Ubuntu. I can read my Ubuntu in Windows.

I don't know how to make a separated partition for the boot: I don't want to mess up my disk. I still can restore to what it was.

[mcbatranu]

I just succeded to create a similar installation of this multi-boot and there are some tricks I feel I should share here. First, I am using Ubuntu 12.10 and Windows 7 (with Truecrypt 7.1a).
After going to the steps described very well by Uborted I further discovered that if I use ext4 filesystem then the entry "insmod ext4" from the config will not work as there is no ext4 module in my /boot folder. On the other hand, I found that on grub2 I can use the ext2 module for all ext# filesystems and so it worked with the entry "insmod ext2".
The next problem was that after reaching the Truecrypt bootloader in the boot sequence I had a problem with the "hidden OS" message which I corrected with the instructions from derfan.
The final problem I had was the after all this, my password was not recognized as ok, so I had to enter the repair menu of the Truecrypt Rescue Disk after the iso was mounted by grub and restore the keyfiles to the drive (option 3 I guess).