How to Perform a Failback-Switchover on a System That Uses Oracle Solaris ZFS Snapshot Replication

Language:

Use this procedure to restart an application on the original primary cluster, paris, after the data on this cluster has been resynchronized with the data on the current primary cluster, newyork.

Note - The failback procedures apply only to clusters in a partnership.

Before You Begin

Before you perform a failback-switchover, a takeover has occurred on newyork. Ensure that the following conditions are met:

If the original primary cluster has been down, the cluster has been booted and the disaster recovery framework infrastructure is enabled on the cluster. For more information about booting a cluster, see Booting a Cluster in Administering the Disaster Recovery Framework for Oracle Solaris Cluster 4.4.
The protection group on the current primary cluster has the primary role.
The protection group on the original primary cluster has either the primary role or secondary role depending on whether the original primary cluster can be reached during the takeover from the current primary cluster.

This procedure uses the example names paris for the original primary cluster and newyork for the current primary cluster.

Ensure that the protection group is stopped at the original primary cluster paris site.
1. Determine whether the protection group on the original primary cluster, paris, is active.
```
paris-node-1# geopg status protection-group
```
2. If the protection group on the original primary cluster is active, stop it.
```
paris-node-1# geopg stop -e local protection-group
```
3. Verify that the protection group is stopped.
```
paris-node-1# geopg status protection-group
```
Resynchronize the original primary cluster, paris, with the current primary cluster, newyork.
The paris cluster forfeits its own configuration and replicates the newyork configuration locally. Resynchronize both the partnership and protection group configurations.
1. On paris, resynchronize the partnership.
```
paris-node-1# geops update partnership
```
  Note - Perform this step only once per partnership even if you are performing a failback-switchover for multiple protection groups in the partnership.
  
  For more information about synchronizing partnerships, see Resynchronizing a Partnership in Administering the Disaster Recovery Framework for Oracle Solaris Cluster 4.4.
2. On paris, resynchronize the protection group.
  Because the local role of the protection group on newyork is now primary, this steps ensures that the role of the protection group on paris becomes secondary.
```
paris-node-1# geopg update protection-group
```
  For more information about synchronizing protection groups, see Resynchronizing a Protection Group in Administering the Disaster Recovery Framework for Oracle Solaris Cluster 4.4.
On paris, validate the cluster configuration for the protection group.
Ensure that the protection group is not in an error state. A protection group cannot be started when it is in an error state.
```
paris-node-1# geopg validate protection-group 
```
For more information, see Validating a Protection Group in Installing and Configuring the Disaster Recovery Framework for Oracle Solaris Cluster 4.4.
On paris, activate the protection group.
Because the protection group on paris has a role of secondary, the geopg start command does not restart the application on paris.
```
paris-node-1# geopg start -e global protection-group
```
–e global

Specifies the scope of the command. The global scope applies the command on both clusters.

protection-group

Specifies the name of the protection group.

Note - Do not use the –n option when performing a failback-switchover. The data must be synchronized from the current primary cluster, newyork, to the current secondary cluster, paris.

Because the protection group has a role of secondary on paris, the data is synchronized from the current primary, newyork, to the current secondary, paris.

For more information about the geopg start command, see How to Activate a Protection Group in Administering the Disaster Recovery Framework for Oracle Solaris Cluster 4.4.
Confirm that the data is completely synchronized.
The status of replication progress is reported by the replication status resources for replication components in the protection group. Check such resource status to determine whether the data has been synchronized. Also, the state of the protection group becomes OK.

To confirm whether the state of the protection group on paris and newyork is OK, use the following command:
```
paris-node-1# geoadm status
newyork-node-1# geoadm status
```
Refer to the Protection group section of the output.

Check the status of the replication status resources for the replication components in the protection group to check that the data is completely synchronized.
```
# clresourcegroup status -v replication-status-rg-for-pg
# clresource status -v replication-status-resource
```
On both partner clusters, ensure that the protection group is activated.
```
# geopg status protection-group
```
On either cluster, perform a switchover from newyork to paris for the protection group.
```
# geopg switchover [-f] -m paris protection-group
```
For more information, see How to Switch Over Replication From the Primary Cluster to the Secondary Cluster in Administering the Disaster Recovery Framework for Oracle Solaris Cluster 4.4.

paris resumes its original role as primary cluster for the protection group.
Ensure that the switchover was performed successfully.
Verify that the protection group is now primary on paris and secondary on newyork and that the state for Data replication and Resource groups is OK on both clusters.
```
# geopg status protection-group
```
Check the runtime status of the application resource group and replication status resource group for the protection group, and the status for each replication status resource associated with a replication component in the protection group.
```
# clresourcegroup status application-rg-in-pg 
# clresource status -g application-rg-in-pg
# clresourcegroup status replication-status-rg-for-pg 
# clresource status -g replication-status-rg-for-pg
```
Refer to the Status and Status Message fields for the replication status resource of each replication component you want to check.

For more information about the runtime status of replication, see Checking the Runtime Status of Oracle Solaris ZFS Snapshot Remote Replication.