My dm-crypt/LUKS mapping does not work! What general steps are there to investigate the problem?
If you get a specific error message, investigate what it claims first. If not, you may want to check the following things. – Check that “/dev”, including “/dev/mapper/control” is there. If it is missing, you may have a problem with the “/dev” tree itself or you may have broken udev rules. – Check that you have the device mapper and the crypt target in your kernel. The output of “dmsetup targets” should list a “crypt” target. If it is not there or the command fails, add device mapper and crypt-target to the kernel. – Check that the hash-functions and ciphers you want to use are in the kernel. The output of “cat /proc/crypto” needs to list them. • My dm-crypt mapping suddenly stopped when upgrading cryptsetup. The default cipher, hash or mode may have changed (the mode changed from 1.0.x to 1.1.x). See under “Issues With Specific Versions of cryptsetup”.
