1. A computer cluster for providing hosting services, comprising: a plurality of nodes, the nodes being responsive to administrative requests; each node including a host operating system and root application software; and each node including a virtual server such that each virtual server responds to user requests and appears to the user as having its own operating system, wherein any virtual servers running on the node share resources of the same host operating system and root application software with other virtual servers of that node; an operating system virtualization layer that allows users to access their virtual servers; a distributed file system that permits private data from each virtual server to be located in the common area and visible to every node and usable for restarting a virtual server.