Improvements in Upgrading Xen-Virtualized Large Computer Systems

With the increasing of software complexity in computing systems, more and more powerful mainframe computing systems begin to use Xen virtualization technology to split the system into several parts, making system maintenance much easier and more targeted while obtaining better operating efficiency. But precisely because of these different system parts running in different Xen-virtualized domains, may also be running in different guest OSes, it is complicated when it comes to overall system upgrade. The commonly used method is synchronized upgrade, which is the next domain will start upgrading until the former one finishes. This approach is very time-consuming and if any error occurs during the upgrade procedure, we have to roll back the entire upgrade procedure to restore the system. In this paper, we present multiple optimizations for upgrading computing systems basing on Xen virtualization technology, so that each domain can be upgraded at the same time with high success rate.