Prerequisites for using vradmin ibc command


Prerequisites for using vradmin ibc command
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Observe the following prerequisites:

The Primary RLINK that points to the Secondary host participating in the vradmin ibc command must be in the connect state.
The onfreeze script must exist on each Secondary host participating in the vradmin ibc command.
Make sure each user-defined script to be used in the vradmin ibc command exits with a status of 0 on successful completion and a status of nonzero on unsuccessful completion.
The user-defined scripts must have execute permissions for root user.
Make sure that scripts have interpreter information in the first line of the IBC shell script. If the first line is a comment or is blank, vradmin ibc does not execute the script.

Caution:

The vradmin ibc executes scripts using root privileges. If the scripts can be modified by a non-privileged user, there is a potential security risk. To prevent this, ensure that you have the proper access privileges set on the scripts used with the vradmin ibc command.

To perform an off-host processing task on one or more Secondary RVGs in an RDS

Make sure the RLINKs are in the CONNECT state. If the RLINKs are not in the CONNECT state, use the vradmin startrep command to start replication.
Create a directory to store the user-defined scripts for this off-host processing task. Create the following directory on all hosts participating in the vradmin ibc command:
```
 /etc/vx/vvr/ibc_scripts/task_name
```
where 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.
Create the appropriate scripts for the required off-host processing task and copy the scripts into the directory created in step 2.
See Understanding the scripts used for the vradmin ibc command.
Run the following command from any host in the RDS:
```
# vradmin -g diskgroup ibc rvg_name task_name [sechost]...[-all]
```
The argument diskgroup represents the disk group that contains the RVG on the local host.

The argument rvg_name is the name of the RVG on the local host and represents its RDS.

The argument task_name is the name of the off-host processing task and is the same as the name of the directory created in step 2.

The argument sechost is the name of the Secondary host as displayed in the output of the vradmin printrvg command. The argument sechost is optional if the RDS contains only one Secondary. To perform the task on multiple Secondary hosts, specify a space-separated list with the name of each Secondary to be included. Use the -all option to perform the task on all the Secondary hosts in the RDS.

Example - Creating a snapshot on the Secondary using the vradmin ibc command

This example shows how to create a snapshot of the data volumes on the Secondary london using the vradmin ibc command. The RVG hr_rvg, which belongs to the disk group hrdg, has been created on the Primary and Secondary. This example also assumes that Secondary data volumes have associated snapshot plexes. It uses the application name dss_app.

Create the following directory on Secondary host:
```
/etc/vx/vvr/ibc_scripts/dss_app
```
Create the onfreeze script in the /etc/vx/vvr/ibc_scripts/dss_app directory on the Secondary host by including the following command to create the snapshot of the data volumes on the Secondary:
```
#!/bin/sh 
/usr/sbin/vxrvg -g hrdg snapshot hr_rvg
```
You can use the vxrvg snapshot command to create instantfull, instantso, or plexbreakoff snapshots.

See VVR command reference.
On the Primary, put the application using the Primary data volumes in the quiesce mode.
Create the snapshot by running the following command on any host in the RDS:
```
# vradmin -g hrdg ibc hr_rvg dss_app london
```
On the Primary, take the application out of quiesced mode to resume it.