This LinuxJournal article by Tom Adelstein includes:
If you're looking to hire a Linux sysadmin, you might need to rethink your hiring guidelines and practices.
...
Converting NT and UNIX system administrators to Linux, however, fails more often than not. Linux system administrators typify a different segment of the population and culture than most trained IT professionals. In general, a Linux system administrator has an easier time working on Microsoft and UNIX operating systems than the other way around.
