25.1.5 Monitor mode and server mode

Organization of this subsection
(1) Functional differences between the monitor mode and the server mode
(2) Cluster software that can be operated in the server mode
(3) Products required for operation in the server mode

(1) Functional differences between the monitor mode and the server mode

The two operation modes for the system switchover facility are the monitor mode and the server mode. When operating in the monitor mode, only system failures are monitored. When operating in the server mode, both system and server failures are monitored. Also, system switchover can be performed more quickly in the server mode. The functional differences between the monitor mode and the server mode are listed in Table 25-8.

Table 25-8 Functional differences between the monitor mode and the server mode

Item or functionMonitor modeServer mode
Failures that are monitoredSystem failures1YesYes
Server failures2NoYes
Function that reduces system switchover timeUser server standby3NoYes
Rapid system switchover facility3NoYes
Standby-less system switchover facilityStandby-less system switchover (1:1) facilityNoYes
Standby-less system switchover (effects distributed) facilityNoYes
Legend:
Yes: Is monitored or can be used.
No: Is not monitored or cannot be used.

1 Errors such as those listed below are assumed to be system failures. However, the conditions for system failures are dependent on the cluster software specifications. For details, check the cluster software documentation or other applicable documentation.

2 Errors such as those listed below are assumed to be server failures.

3 This is a function that reduces the system switchover time. For details about user server hot standby and the rapid system switchover facility, see 25.18 Reducing system switchover time (user server hot standby, rapid system switchover facility).

(2) Cluster software that can be operated in the server mode

Some cluster software cannot operate in the server mode. Cluster software that can be operated in the server mode is listed in Table 25-9.

Table 25-9 Cluster software that can be operated in the server mode

Cluster softwareMonitor modeServer mode
HA monitorYesYes
MC/ServiceGuardYesYes
VERITAS Cluster ServerYesYes
Sun ClusterYesNo
HACMPYesNo
ClusterPerfectYesNo
Legend:
Yes: Can be operated in this mode.
No: Cannot be operated in this mode.
Note
In the Linux (EM64T) version, the system switchover facility in the server mode is not supported.

(3) Products required for operation in the server mode

The products required to operate the system switchover facility in the server mode are listed in Table 25-10.

Table 25-10 Products required for operation in the server mode

FunctionHiRDB Advanced High AvailabilityHitachi HA Toolkit Extension
Server mode--Required#
User server hot standby--Required#
Rapid system switchover facility--Required#
Standby-less system switchover (1:1) facilityRequiredRequired#
Standby-less system switchover (effects distributed) facilityRequiredRequired#
Legend:
Required: This product is required for operation in the server mode.
--: Not required.

# When the cluster software being used is HA monitor, Hitachi HA Toolkit Extension is not required.