Creating a switchable hardware group

 

Create a switchable hardware group, also known as a device cluster resource group (CRG).

The switchable hardware group contains a list of switchable devices. Each device in the list identifies a switchable independent disk pool. The entire collection of devices are switched to the backup node when an outage, planned or unplanned, occurs. Optionally, the devices can also be made available (varied on) as part of the switchover or failover process.

A switchable hardware group identifies a device domain. A device domain is a subset of cluster nodes that share a set of resilient devices. The device domain is created automatically when you use the iSeries™ Navigator wizard to create a cluster. If you are using cluster CL commands and APIs, add each node that you want to be switchable to the device domain.

Using iSeries Navigator (requires Option 41 (i5/OS® - HA Switchable Resources))

The New Switchable Hardware Group wizard will take you through the steps to create a new switchable hardware group and add a disk pool to it for the cluster.

To add a switchable hardware group, follow these steps:

  1. In iSeries Navigator, expand Management Central.

  2. Expand Clusters.

  3. Expand the cluster for which you need to add a switchable hardware group.

  4. Right-click Switchable Hardware, and select New Group.

  5. By default the New Disk Pool wizard creates a protected disk pool that allows you to choose how you want to protect the disk units. You can use device parity protection, mirrored protection, or a combination of both. After the disk pool is created, you are prompted to start disk unit mirroring. This ensures that if you make changes to your disk pool configuration, it will remain protected. You can also create an unprotected disk pool by unchecking the protection option.

Make sure that all the nodes in the recovery domain are started.

 

Using Cluster CL commands and APIs

You can also use the following to add a device domain entry and create a device cluster resource group:

 

Add Device Domain Entry

Adds a node to a device domain membership list so that it can participate in recovery actions for resilient devices. The addition of the first node to a device domain has the effect of creating that device domain.

 

Create Cluster Resource Group

Creates a cluster resource group object. The cluster resource group object identifies a recovery domain, which is a set of nodes in the cluster that will play a role in recovery.

 

Parent topic:

Creating a switchable independent disk pool
Related tasks
Creating a switchable independent disk pool Configuring geographic mirroring with switchable independent disk pools