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| Understanding the scripts used for the vradmin ibc command | ||
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| Prev | Using the IBC messaging command vradmin ibc | Next |
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| Understanding the scripts used for the vradmin ibc command | ||
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| Prev | Using the IBC messaging command vradmin ibc | Next |
The vradmin ibc command executes the user-defined scripts: prefreeze, quiesce, unquiesce, onfreeze, and postfreeze. Note that the onfreeze script is mandatory and must be present on the Secondary. The scripts prefreeze, quiesce, unquiesce, and postfreeze are optional. However, if you provide the quiesce script, you must provide the unquiesce script and vice versa. You must name the user-defined scripts prefreeze, quiesce, unquiesce, onfreeze, or postfreeze.
The following describes how each script is used with the vradmin ibc command:
The prefreeze script
Use this script on the Secondary to prepare for the tasks to be performed in the onfreeze script while the replication to Secondary is frozen. For example, if you want to take a snapshot of the Secondary data volumes while the replication on the Secondary is frozen, the prefreeze script can be used to add snapshot plexes to the Secondary data volumes to prepare for the snapshot command.
The quiesce script
The vradmin ibc command executes the quiesce script on the Primary before it sends the IBC message to the Secondary. Use this script to quiesce the application running on the Primary RVG and to make the Primary data volumes consistent at the application level. The vradmin ibc command injects an IBC message in a small amount of time, and hence the duration for which the application remains quiesced is small.
The unquiesce script
The vradmin ibc command executes this script on the Primary after it sends the IBC message to the Secondary. Use this script to resume the application running on the Primary if the application was quiesced.
The onfreeze script
The vradmin ibc command executes this script on the Secondary while replication on the Secondary is frozen after receiving the IBC message from the Primary. Use this script to perform the required off-host processing operation, for example, taking a snapshot of the Secondary data volumes.
The postfreeze script
The vradmin ibc command executes this script on the Secondary after it executes the onfreeze script and after the replication on the Secondary is unfrozen. For example, if a snapshot of the Secondary data volumes was taken in the onfreeze script, this script can be used to reattach the snapshot volumes to the Secondary data volumes.
The scripts must reside in the /etc/vx/vvr/ibc_scripts/task_name directory on the Primary and the Secondary host. Note that task_name is the name of the off-host processing task and is the same as the task_name argument used in the vradmin ibc command. For example, if the off-host processing task is Decision Support Systems (DSS), you can choose a task name of dss; or if the off-host processing task is Backup, you can choose the task name of backup.
Table: Locations of the scripts for off-host processing shows the locations of the scripts for off-host processing.
Table: Locations of the scripts for off-host processing
In a shared disk group environment, the scripts must exist on each node in the Primary or Secondary cluster. That is, the quiesce and unquiesce scripts must exist on each node in the Primary cluster; the onfreeze, prefreeze, and postfreeze scripts must exist on each node in the Secondary cluster.
When the vradmin ibc command executes each script, it passes the following arguments to the script: