What is the main function of machine

When building a cluster between guests in different units on a virtual machine, if an error occurs in the host OS, nodes in the cluster may enter the LEFTCLUSTER state. Host OS failover function allows for automatically switching cluster applications on the guest OSes in the case of the following errors in a cluster system between guests in different units in a Xen environment or a KVM environment.

- Panic of the host OS

- Hang-up of the host OS (slowdown)

This function is achieved by linking PRIMECLUSTER installed on the host OS with guest OSes.

Note that there are some precautions for operations, for example, setting the priority of RMS is not available by using this function. Then, you should take these precautions into consideration when designing the system.


  • When creating a cluster application for a guest OS, do not set the ShutdownPriority attribute of RMS.

  • When a host OS failure is detected, the host OS is forcibly shut down. Then, all guest OSes on that host OS with a failure will stop regardless of whether they are clusters or not.

  • Do not build any cluster applications on the host OS.

Figure 2.1 Cluster system using the Host OS failover function on the virtual machine

Figure 2.2 Failover image in the case of host OS failure