To use the full power of the kernel based linux-vserver concept, several user space utilities are needed. On the one side there are simple tools like low-level syscall wrappers, or enhancements of well-known UNIX utilities like ps or kill. The other side is the management of the virtual servers (VS). Mostly, these VS are chroot environments and are based on ordinary Linux distributions which are not prepared for VS usage. Note, that the VS is independent from the host distribution: it is possible to have Debian and Gentoo VS on a Fedora Core host system (and vice versa). So the tools are providing methods to bootstrap a VS from scratch, mechanisms to start and stop VS (inclusive setting up networking and general machine parameters) and ways to share diskspace between VS. Because isolation of untrusted applications and selling to unstrusted customers are typical VS applications, these management tasks must be done in a secure way. The presentation will show the creation of Fedora Core and Debian based VS, their operation and which precautions were taken to prevent manipulations. The configuration scheme which is used by 'util-vserver' to manage the VS will be introduced too.
Enrico Scholz is a student of computer science at the Chemnitz University of Technology and is paid by SIGMA Chemnitz GmbH for developing software and administrating the network. In his spare time he works on some small projects, designed and implemented the fedora.us buildsystem, and maintains the util-vserver package since 2003. He gave some talks at local linux events, and lives, studies and works in Chemnitz.
