How to Perform a Failback-Switchover on a System That Uses Oracle ZFS Storage Appliance Replication

Language:

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

Note - The failback procedures apply only to clusters in a partnership. You need to perform the following procedure only once per partnership.

Before You Begin

Before you perform a failback-switchover, a takeover has occurred on cluster-newyork. Ensure that the clusters have the following roles:

If the original primary cluster had been down, the cluster has been booted and that the Geographic Edition infrastructure is enabled on the cluster. For more information about booting a cluster, see Booting a Cluster in Oracle Solaris Cluster Geographic Edition System Administration Guide.
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 cluster-paris for the original primary cluster and cluster-newyork for the current primary cluster.

Synchronize replication from the newyork appliance to the paris appliance.
This task is necessary to finish recovery if the cluster had experienced a complete site failure or a takeover. Data stores at cluster-newyork will have changed and will need to be replicated back to cluster-paris when it is put back in service.

Perform these steps for each project that is replicated.
1. Access the Oracle ZFS Storage Appliance browser user interface (BUI) on the cluster-newyork site.
2. Navigate to Shares > Projects and select the project being replicated.
3. Select Replication for the project and click Update now.
  This executes a manual replication to synchronize the two sites.
Ensure that the protection group is stopped at the cluster-paris site.
1. Determine whether the protection group on the original primary cluster, cluster-paris, is active.
```
phys-paris-1# geoadm status
```
2. If the protection group on the original primary cluster is active, stop it.
```
phys-paris-1# geopg stop -e local protection-group
```
  protection-group
  
  Specifies the name of the protection group
3. Verify that the protection group is stopped.
```
phys-paris-1# geoadm status
```
Remove obsolete projects from the appliance at the cluster-paris site.
1. Access the BUI on the cluster-paris site.
2. Navigate to Shares > Projects.
3. If any projects in the protection group are listed, manually delete them.
Resynchronize the original primary cluster, cluster-paris, with the current primary cluster, cluster-newyork.
The cluster-paris cluster forfeits its own configuration and replicates the cluster-newyork configuration locally. Resynchronize both the partnership and protection group configurations.
1. On cluster-paris, resynchronize the partnership.
```
phys-paris-1# geops update partnership
```
  partnership
  
  Specifies the name of the 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 Oracle Solaris Cluster Geographic Edition System Administration Guide.
2. On cluster-paris, resynchronize each protection group.
  Because the local role of the protection group on cluster-newyork is now primary, this steps ensures that the role of the protection group on cluster-paris becomes secondary.
```
phys-paris-1# geopg update protection-group
```
  For more information about synchronizing protection groups, see Resynchronizing a Protection Group in Oracle Solaris Cluster Geographic Edition System Administration Guide.
On cluster-paris, validate the cluster configuration for each protection group.
Ensure that the protection group is not in an error state. A protection group cannot be started when it is in a error state.
```
phys-paris-1# geopg validate protection-group 
```
protection-group

Specifies a unique name that identifies a single protection group

For more information, see Validating a Protection Group in Oracle Solaris Cluster Geographic Edition Installation and Configuration Guide.
On cluster-paris, activate each protection group.
Because the protection group on cluster-paris has a role of secondary, the geopg start command does not restart the application on cluster-paris.
```
phys-paris-1# geopg start -e global protection-group
```
–e global

Specifies the scope of the command. By specifying a global scope, the command operates 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, the data is synchronized from the current primary, cluster-newyork, to the current secondary, cluster-paris.

For more information about the geopg start command, see How to Activate a Protection Group in Oracle Solaris Cluster Geographic Edition System Administration Guide.
Confirm that the data is completely synchronized.
The data is completely synchronized when the state of the protection group on cluster-newyork is OK. The protection group has a local state of OK when the appliance data store on cluster-newyork is being updated to the cluster-paris cluster.

To confirm that the state of the protection group on cluster-newyork is OK, use the following command:
```
phys-newyork-1# geoadm status
```
Refer to the Protection Group section of the output.
On both partner clusters, ensure that the protection group is activated.
```
# geoadm status
```
On either cluster, perform a switchover from cluster-newyork to cluster-paris for each protection group.
```
# geopg switchover [-f] -m cluster-paris protection-group
```
For more information, see How to Switch Over Replication From the Primary Cluster to the Secondary Cluster in Oracle Solaris Cluster Geographic Edition System Administration Guide.

cluster-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 cluster-paris and secondary on cluster-newyork and that the state for “Data replication” and “Resource groups” is OK on both clusters.
```
# geoadm status
```
Check the runtime status of the application resource group and replication for each protection group.
```
# clresourcegroup status -v protection-group
```
Refer to the Status and Status Message fields that are presented for the remote replication component you want to check.

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

For more information on how to perform the switchover, see Migrating Replication Services by Switching Over Protection Groups.