The most important skill set requirement is deep knowledge of the technologies that underlie the high-availability system. Most high-availability involves clustering, so deep knowledge of clustering is also highly desirable.
Your team must also be well disciplined in order to carry out job functions scrupulously and document in a run book every change they make. Failure to do so may result in unplanned downtime.
Finally, the team must be highly reactive to crisis situations, while providing a high level of service.
This was first published in December 2007