Two technologies combined in one great solution ...

Virtualization technologies are used to enhance the hardware load on server systems and allow a more efficient use of those servers. Nowadays, there is a wide range of existing HA solutions which guarantee the availability of all virtual machines. There are just a few commercial solutions available for allocating virtual machines during their operation time to optimize the actual server workload (e.g. VMware DRS, VirtualIron LiveCapacity). A generic solution for all kinds of virtualization technologies is non existent today.

Virtualization technologies allow to optimize the actual server workload, but present a single point of failure for all virtualized systems. The Red Hat Cluster Suite is an approved solution for high availability and used in our project to combine virtualization and load balancing.

The LBVM consists of several scripts that allow to load balance virtual machines (currently preconfigured: Xen and OpenVZ) among physical servers - the algorithm is fully configurable. LBVM uses the Red Hat Cluster Suite to provide high availability and rgmanager (part of the Red Hat Cluster Suite) to perform the actual migration. Developed cluster scripts for Xen and OpenVZ allow the rgmanager to perform live migrations with zero-downtime to provide maximum reliability and uptime. The load balancing algorithm uses preconfigured resources (cpu, mem, load; fully configurable) to decide when and where to move a virtual machine. Reports and migrations are logged and also available in human-readable format.

RPM packages allow to easily integrate and update the LBVM in a running environment. An existing virtual machine can be transformed to a clustered, load balanced machine with a single command.

LBVM is an optimized solution for critical services and offers high availability as well as load sharing among servers to guarantee an efficient use of physical devices. Another advantage is that it can be easily implemented and adapted to meet the requirements of enterprise environments.