SunOS to Linux Migration?

phuzzie asks: "I'm in the process of switching our server from a single SunOS [intel] box to several Slackware Linux boxes. However, I'm running into a couple snags. Namely the fact that SunOS allowed us to have greater than 8 character usernames, whereas Slackware doesn't. Does anyone know if there is a way to make Linux use >8 char usernames? Also, I need to know if the shadow crypt and the /etc/passwd are the same between Linux and SunOS [ie do I have to re-enter all of our 3000 users or can I just copy the files over?]. Any help anyone has to offer about any other issues dealing with this sort of migration would also be greatly appreciated." Are there any other Sun-to-Linux snags to be wary of?