I understood something different by "while disk encryption". I thought it meant encrypting the whole disk (partition table and all) not just the partitions on it.
Goebel Consult, Landshut
http://www.goebel-consult.de
Blog:
http://www.goebel-consult.de/blog/vorratsdatenspeicherung-jetzt-verfassungsbeschwerde-unterschreiben
Kolumne:
http://www.cissp-gefluester.de/2010-07-passwoerter-lieben-lernen