1.4 Hot-standby switchover methods

The following hot-standby switchover methods can be used with HA Monitor:

• Hot-standby switchover based on hybrid fencing

• Hot-standby switchover based on a host reset

• Hot-standby switchover based on SCSI reservation for shared disk

• Hot-standby switchover based on the availability of LAN communications

For HA Monitor, we recommend hot-standby switchover based on hybrid fencing. This method has the following advantages:

• Even if host reset cannot be performed due to, for example, a failure of the failure management processor (SVP or VMware ESXi), the system can continue to perform hot-standby switchover by using a SCSI-reserved shared disk. Because the reliability of automatic hot-standby switchover in the event of a host failure is higher than other methods, system availability can be improved.

• The failed host can be stopped and isolated completely by resetting the host, which prevents the same server from starting on multiple hosts as active servers. Thus, safe hot-standby switchover can be performed.

• A dump can be obtained if an OS slowdown occurs.

If hot-standby switchover based on hybrid fencing cannot be selected, hot-standby switchover based on host reset is recommended. Hot-standby switchover based on host reset has the following advantages:

• The failed host can be stopped and isolated completely by resetting the host, which prevents the same server from starting on multiple hosts as active servers. Therefore, safe hot-standby switchover can be performed.

• A dump can be obtained if OS slowdown occurs.

Note, however, that the hot-standby switchover methods that can be selected differ depending on the system configuration and requirements. Select a hot-standby switchover method based on the information in the following table.

Table 1‒3: Selecting a hot-standby switchover method

System configuration (server model)	Hot standby method
BladeSymphony or HA8000	In a virtualization environment in which access to VMware and the failure management processor is permitted: Select either of the following methods: • Hot-standby switchover based on hybrid fencing • Hot-standby switchover based on host reset In a virtualization environment in which access to VMware and the failure management processor is prohibited: Hot-standby switchover based on SCSI reservation for shared disk In a non-virtualization environment (physical environment): Select either of the following methods: • Hot-standby switchover based on hybrid fencing • Hot-standby switchover based on host reset
Non-Hitachi PC/AT-compatible system	In an environment that uses a shared disk: Hot-standby switchover based on SCSI reservation for shared disk In an environment that does not use a shared disk: Hot-standby switchover based on the availability of LAN communications

To Page Top