Dell says that Linux now makes up 25 percent of its enterprise market.
"As part of Dell Service we have managed over 500 Unix to Linux migrations," Parker told ZDNet UK. "We see that growing, not shrinking, over time."
Linux is now "over a quarter of what we sell", said Parker.
Virtually all of the business has come from customer migrations from proprietary Unix environments, from companies such as IBM and Sun.
"We have been successful in helping customers convert from Unix," said Parker. "What those customers feel most comfortable with is what they view as an open source version of Unix. They feel comfortable with the capability and reliability of Linux."