Creating a Truecrypt partition that uses the ext3 filesystem

For reasons given in another post I decided that I wanted the external data hard drives on my Xubuntu laptop home server to be encrypted, and I wanted the encrypted partitions to use the ext3 filesystem. The only thing that makes this challenging at all is that there no option on the Truecrypt GUI to create a volume with the ext3 file system. The only options on the GUI are FAT and None.

The first step was to install Truecrypt. For some reason its not in the Ubuntu repositories, you I downloaded a Deb package from the Truecrypt website and used the script that came with it to install. Pretty easy.

First I launched the truecrypt GUI by opening a terminal and running:

truecrypt

Then I plugged in the external drive and looked do see where it mounted as a device:

ls /dev/sd*

I knew sda and sda1 were the system hard drive, so sdb and sdb1 had to be the external drive, and I knew from experience that I wanted to create the Truecrypt partition on sdb1 and not sdb.

Using the Truecrypt GUI I told it to create a new encrypted partition on /dev/sdb1 but specified None for file system instead of FAT, and chose Quick Format (despite the warnings) since I knew the disk had previously been written over with random data on previous encryption efforts.

Once the new encrypted partition was created I used the GUI to mount it, being careful to click the button for options, and then checking the box for mounting without a file system.

Once the new encrypted partition was mounted without a file system I looked up its mount point in a terminal:

truecrypt -l

And saw that it was at /dev/mapper/truecrypt1.

Then I formatted it with the ext3 filesystem with the following command:

sudo mkfs.ext3 /dev/mapper/truecrypt1

Once it was done I dismounted the Truecrypt partition:

truecrypt -d

And then I remounted it from the command line:

truecrypt /dev/sdb1 /media/truecrypt1

Then I did chown and chmod on mount its mount point.

sudo chown nobody:nogroup /media/truecrypt1
sudo chmod -R a+rw /media/truecrypt1

That seemed to work for me!