A switchable hardware group, also known as a device cluster resource group (CRG), 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, you must add each node that you want to be switchable to the device domain.
You can also use the following to add a device domain entry and create a device cluster resource group:
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.
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.