Before you begin creating protection groups, consider which of the following strategies is best for you:
Taking the application offline before creating the protection group
This strategy is the most straightforward because you use a single command to create the protection group on one cluster, retrieve the information on the other cluster, and start the protection group. However, because the protection group is not brought online until the end of the process, you must take the application resource group offline to add it to the protection group.
Creating the protection group while the application remains online
While this strategy allows you to create a protection group without any application outage, it requires issuing more commands.
The following sections describe the steps to take for each strategy.
The steps to take to create a protection group while the application resource groups is offline follow:
Create the protection group from a node on one cluster.
For more information, see How to Create and Configure a Hitachi TrueCopy Protection Group.
Add the data replication device group to the protection group.
For more information, see How to Add a Data Replication Device Group to a Hitachi TrueCopy Protection Group.
Take the application resource group offline.
Add the application resource group to the protection group.
For more information, see How to Add an Application Resource Group to a Hitachi TrueCopy Protection Group.
On the other cluster, retrieve the protection group configuration.
For more information, see How to Replicate the Hitachi TrueCopy Protection Group Configuration to a Partner Cluster.
From either cluster, start the protection group “globally”.
For more information, see How to Activate a Hitachi TrueCopy Protection Group.
To add an existing application resource group to a new protection group without taking the application offline, complete the following steps on the cluster where the application resource group is online.
Create the protection group from a node on one cluster.
For more information, see How to Create and Configure a Hitachi TrueCopy Protection Group.
Add the data replication device group to the protection group
For more information, see How to Add a Data Replication Device Group to a Hitachi TrueCopy Protection Group.
Start the protection group locally.
For more information, see How to Activate a Hitachi TrueCopy Protection Group.
Add the application resource group to the protection group.
For more information, see How to Add an Application Resource Group to a Hitachi TrueCopy Protection Group.
Complete the following steps on the other cluster.
Retrieve the protection group configuration.
For more information, see How to Replicate the Hitachi TrueCopy Protection Group Configuration to a Partner Cluster.
Activate the protection group locally.
For more information, see How to Activate a Hitachi TrueCopy Protection Group.
This example describes how to create a protection group without taking the application offline.
In this example, the apprg1 resource group is online on the cluster-paris cluster.
Create the protection group on cluster-paris.
phys-paris-1# geopg create -d tc -p Nodelist=phys-paris-1,phys-paris-2 -o Primary \ -s paris-newyork-ps tcpg Protection group "tcpg" has been successfully created |
Add the device group, tcdg, to the protection group.
phys-paris-1# geopg add-device-group -p fence_level=async tcdg tcpg |
Activate the protection group locally.
phys-paris-1# geopg start-e local tcpg Processing operation.... this may take a while.... Protection group "tcpg" successfully started. |
Add an application resource group that is already online to the protection group.
phys-paris-1# geopg add-resource-group apprg1 tcpg Following resource groups were successfully inserted: "apprg1" |
Verify that the application resource group was added successfully.
phys-paris-1# geoadm status Cluster: cluster-paris Partnership "paris-newyork-ps" : OK Partner clusters : newyork Synchronization : OK Heartbeat "hb_cluster-paris~cluster-newyork" monitoring \ "paris-newyork-ps" OK Plug-in "ping-plugin" : Inactive Plug-in "icrm_plugin" : OK Plug-in "tcp_udp_plugin" : OK Protection group "tcpg" : Degraded Partnership : paris-newyork-ps Synchronization : OK Cluster cluster-paris : Degraded Role : Primary Configuration : OK Data replication : Degraded Resource groups : OK Cluster cluster-newyork : Unknown Role : Unknown Configuration : Unknown Data Replication : Unknown Resource Groups : Unknown |
On one node of the partner cluster, retrieve the protection group as follows:
phys-newyork-1# geopg get -s paris-newyork-ps tcpg Protection group "tcpg" has been successfully created. |
Activate the protection group locally on the partner cluster.
phys-newyork-1# geopg start-e local tcpg Processing operation.... this may take a while.... Protection group "tcpg" successfully started. |
Verify that the protection group was successfully created an activated.
Running the geoadm status command on cluster-parisproduces the following output:
phys-paris-1# geoadm status Cluster: cluster-paris Partnership "paris-newyork-ps" : OK Partner clusters : newyork Synchronization : OK Heartbeat "hb_cluster-paris~cluster-newyork" monitoring \ "paris-newyork-ps": OK Plug-in "ping-plugin" : Inactive Plug-in "icrm_plugin" : OK Plug-in "tcp_udp_plugin" : OK Protection group "tcpg" : Degraded Partnership : paris-newyork-ps Synchronization : OK Cluster cluster-paris : Degraded Role : Primary Configuration : OK Data replication : Degraded Resource groups : OK Cluster cluster-newyork : Degraded Role : Secondary Configuration : OK Data Replication : Degraded Resource Groups : OK |