Despite trying both with the GUI and command line, sdcreate insists on using the size of the second partition when creating the volume on the 3rd one.
I have used gparted to partition my 100 GB drive as follows:
Number Start End Size Type File system Flags
1 32.3kB 75.5GB 75.5GB primary ext4
2 75.5GB 76.0GB 535MB primary linux-swap
3 76.0GB 100GB 24.0GB primary
My intent is to use the last partition as an encrypted container. I have attempted to do this a number of times, both with the GUI, and via command line, with the same result. When I use the GUI, the size displayed during the creation process is around 21-24 GB. Once everything has run, and I mount the encrypted volume, its size is that of the second partition on the drive. I've gotten this result both when I've partitioned it with a half GB swap partition, and with a whole GB swap partition.
Here is the command I was running:
sudo sdcreate -c /dev/sda3 -format truecrypt6 -digest sha512 -cipher aes -gb 23.5
I'm running scramdisk via a full Ubuntu 9.04 install on an external USB hard disk. sda is my internal hard disk. I was later planning on installing ubuntu on the first partition, with the second as the swap, but my first priority is to set up the last partition as an encrypted volume