2.4.1 Resources that can be inherited and their units
HA Monitor enables the following types of resources to be inherited:
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Shared disks
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File systems
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LANs
In addition to the above types of resources, other resources can also be inherited by HA Monitor if you create a user command beforehand.
- Unit of inheritance
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Shared resources are inherited for each server. To share a single shared resource among multiple servers, you can provide a dedicated server called a resource server.
- Prevention of conflict on shared resources
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If separation of a shared resource fails in the active system during the hot standby operation, a conflict might occur in accesses to the shared resource, resulting in corruption of the shared resource and system shutdown. To prevent both hosts from conflicting with each other for a shared resource, HA Monitor forcibly stops the active system to perform hot-standby switchover in the following cases:
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If disconnection of a shared resource fails during the processing of hot-standby switchover
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If disconnection processing times out with the timeout value specified for the dev_timelimit and dev_offlimit operands in the server environment definition
The method used to forcibly stop the active system differs depending on the condition in which hot-standby switchover is performed if a host failure occurs.
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If host reset is to be performed: Host is reset.
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If SCSI reservation for shared disk is used or the function for controlling hot standby based on the availability of LAN communications is used: The host that failed to separate the shared resource shuts down the OS by generating a kernel panic.
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