This section provides instructions for creating a virtual storage machine (VSM) in the secondary storage system and configuring it for GAD pair operations. When you create a virtual storage machine (VSM), there are two procedures: VSM auto-configuration and VSM manual configuration.
VSM manual configuration
Creating a virtual storage machine by using a resource group is referred to as VSM manual configuration. To perform VSM manual configuration, you need to install Resource Partition Manager.
In VSM manual configuration, reserve resource information (such as the host group ID and LDEV ID) for the resource group created for a virtual storage machine. Create a host group and an actual volume by specifying the reserved IDs. Then those resources can be used for a GAD pair.
VSM auto-configuration
Creating a virtual storage machine without using a resource group is referred to as VSM auto-configuration. When you perform VSM auto-configuration, you don't need to install Resource Partition Manager, which simplifies the configuration procedure compared with VSM manual configuration. VSM auto-configuration is supported by DKCMAIN microcode version A0-05-41 and later.
If a volume with a namespace on NVMe-oF defined is used as a P-VOL of a GAD pair in the initial state, a namespace must also be defined on a volume used as an S-VOL of the GAD pair. For details, see Initial state.
A GAD pair can be created only when both the P-VOL and the S-VOL are volumes (LUs) with LU paths defined, or both are volumes with namespaces on NVMe-oF defined. The following procedures apply for each case with LUs or namespaces defined.
The following procedures describe how to create a GAD environment. If appropriate, you can use existing storage system resources, for example, Dynamic Provisioning pools and DP-VOLs that have already been created.