InfoScale™ 9.0 Cluster Server Agent for Hitachi TrueCopy/HP-XP Continuous Access Configuration Guide - Windows
- Introducing the agent for Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Configuring the agent for Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Configuration concepts for the Hitachi TrueCopy/Hewlett-Packard XP Continuous Access agent
- Resource type definition for the Hitachi TrueCopy agent
- Attribute definitions for the TrueCopy/HP-XP-CA agent
- Sample configuration for the TrueCopy/HP-XP-CA agent
- Before you configure the agent for Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Configuring the agent for Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Configuration concepts for the Hitachi TrueCopy/Hewlett-Packard XP Continuous Access agent
- Testing VCS disaster recovery support with Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- How VCS recovers from various disasters in an HA/DR setup with Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Testing the global service group migration
- Testing disaster recovery after host failure
- Testing disaster recovery after site failure
- Performing failback after a node failure or an application failure
- Performing failback after a site failure
- Setting up fire drill
About the Hitachi TrueCopy/Hewlett-Packard XP Continuous Access agent's online function
If the state of all local devices is read-write enabled, the agent makes the devices writable by creating a lock file on the local host. The agent considers the P-VOL devices writable and takes no action other than going online, regardless of their status.
If the state of all local devices is SMPL (Simplex), then the AllowOnlineOnSimplex attribute is honored to allow/disallow resource to come online.
If one or more devices are not in a writable state, the agent runs the horctakeover command to enable read-write access to the devices. If the horctakeover command exits with an error (exit code > 5), for example, due to a timeout, then the agent flushes and freezes the group to indicate that user-intervention is required to identify the cause of the error.
For S-VOL devices in any state other than SSWS and SSUS, the agent honors the SplitTakeover attribute and runs the horctakeover command to make the devices writable.
The time required for failover depends on the following conditions:
The health of the original primary.
The RAID Manager timeouts as defined in the horcm configuration file for the device group.
If the S-VOL devices are in the SSUS state and if the RoleMonitor attribute is set to 1, the agent runs the pairdisplay command without the -l option, to determine if the S-VOL is in a writable state. The agent behavior when devices are in S-VOL SSUS state is as follows:
If S-VOL devices are in SSUS writable state, the agent proceeds with online without failover.
If S-VOL devices are in SSUS read only state, the agent honors the SplitTakeover attribute and accordingly proceeds with failover to make the devices writable.
In case agent could not connect to remote RAID manager, the agent faults the resource.
If the S-VOL devices are in the COPY state, the agent runs the horctakeover command after one of the following:
The synchronization from the primary completes.
When the OnlineTimeout period of the entry point expires, the horctakeover command will not be executed, in which case the resource faults.
If S-VOL devices are in the PAIR state, the agent issues the pairdisplay command without the -l option to get the replication link state. If it finds that the P-VOL devices are in the PAIR state, the agent proceeds with failover. If remote horcm is down, the SplitTakeover attribute is honored before issuing the horctakeover command. The agent validates the value of OnlineTimeout for the HTC type is sufficient to run the horctakeover command. If the agent finds this value of OnlineTimeout is insufficient, the agent logs an appropriate error message.