Overview of SVC management

It is an in-band implementation that minimizes the dependency on unique hardware and software, telecopying the storage functions expected in a SAN environment from the storage subsystems and managing storage resources. In addition, it provides advanced copy services for data migration and business continuity similar to the Peer to Peer Remote Copy function in the ESS and DS4000® (formerly named the FAStT) Storage subsystems. Since the copy services operate on the virtual volumes, dramatically simpler replication configurations can be created using the SAN Volume Controller, rather than replicating each physical volume in the managed storage pool.

PowerHA® SystemMirror® Enterprise Edition for Metro Mirror with SVC management enhances PPRC's ability to provide a fully automated, highly available disaster recovery management solution by taking advantage of SVC's ability to provide virtual disks derived from varied disk subsystems. The PowerHA SystemMirror interface is designed so that once the basic SVC environment is configured, PPRC relationships are created automatically; no additional access to the SVC interface is needed.

PowerHA SystemMirror configuration information required for SVC PPRC resource management is simple; it is easily acquired from the existing SVC configuration.

The integration of PowerHA SystemMirror and SVC PPRC provides:

• PowerHA SystemMirror management of SVC PPRC for automatic fallover/reintegration of SVC PPRC-protected virtual disks between PowerHA SystemMirror sites
• Support for user-defined policy-based resource groups
• Support for the following Inter-Site Management Policies for resource groups:
  • Prefer Primary Site
  • Online on Either Site.
• Support for the Subsystem Device Driver (SDD) (for the 2145 (SVC) system)
• Support for cluster verification and synchronization
• Flexible user-customizable resource group movement policies
• Limited support for C-SPOC (PowerHA SystemMirror Single Point of Control utility)
• Automatic fallover/reintegration of server nodes attached to SVC-provided virtual disk pairs within sites
• Management of automatic fallover of PPRC-protected volume groups between nodes within a site
• SVC management to switch the SVC PPRC relationships over so that the backup site can take control of the PowerHA SystemMirror-managed resource groups from the primary site in case of a site failure
• SVC PPRC Command Line Interface or GUI to manually manage SVC PPRC consistency groups and relationships.

It is important to understand how the terms primary and auxiliary are used in the PowerHA SystemMirror Enterprise Edition Metro Mirror for the SVC environment. In general, primary and auxiliary refer to the SVC virtual disks that are on either end of a SVC PPRC link. Primary and secondary refer to the PowerHA SystemMirror sites that host the resource groups that manage the SVC PPRC replicated resources that contain those SVC PPRC links.

The terms primary and auxiliary can also refer to the SVC clusters themselves. In general, the primary SVC cluster is connected to the PowerHA SystemMirror production site, and the auxiliary SVC cluster is connected to the PowerHA SystemMirror backup and recovery site.