HP P4000 9.0 HP StorageWorks P4000 SAN Solution User Guide - Page 170

When to use a virtual manager, Disaster recovery using a virtual manager

Page 170 highlights

When to use a virtual manager Use a virtual manager in the following configurations: • A management group across two sites with shared data • A management group in a single location with two storage systems Use a virtual manager for disaster recovery in a two-site configuration, or a two-system configuration. You can also use a virtual manager to maintain quorum during storage system maintenance procedures, such as firmware upgrades. Disaster recovery using a virtual manager The virtual manager functions as an on-demand manager in a disaster-recovery situation. As an on-demand manager, it can be used to regain quorum and maintain access to data. Management group across two sites with shared data Using a virtual manager allows one site to continue operating if the other site fails. The virtual manager provides the ability to regain quorum in the operating site if one site becomes unavailable, or in one selected site if communication between the sites is lost. Such capability is necessary if volumes in the management group reside on storage systems in both locations. Management group in a single location with two storage systems If you create a management group with only two storage systems, that management group is not a fault-tolerant configuration. Using one manager provides no fault tolerance. Using two managers also provides no fault tolerance, due to loss of quorum if one manager becomes unavailable. See "Managers and quorum" on page 149 for more information. Running two managers and adding a virtual manager to this management group provides the capability of regaining quorum if one manager becomes unavailable. Storage system maintenance using a virtual manager A virtual manager can also be used during maintenance to prevent loss of quorum. Adding a virtual manager to a management group enables you to start the virtual manager when you need to take a storage system offline for maintenance. Benefits of a virtual manager Running a virtual manager supports disaster-tolerant configurations to support full-site failover. The virtual manager ensures that, in the event of either a failure of a storage system running a manager, or of communication breakdown between managers (as described in the two-site scenario), quorum can be recovered and, hence, data remains accessible. Requirements for using a virtual manager It is critical to use a virtual manager correctly. A virtual manager is added to the management group, but not started on a storage system until the management group experiences a failure and a loss of 170 Using specialized managers

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When to use a virtual manager
Use a virtual manager in the following configurations:
A management group across two sites with shared data
A management group in a single location with two storage systems
Use a virtual manager for disaster recovery in a two-site configuration, or a two-system configuration.
You can also use a virtual manager to maintain quorum during storage system maintenance procedures,
such as firmware upgrades.
Disaster recovery using a virtual manager
The virtual manager functions as an on-demand manager in a disaster-recovery situation. As an
on-demand manager, it can be used to regain quorum and maintain access to data.
Management group across two sites with shared data
Using a virtual manager allows one site to continue operating if the other site fails. The virtual manager
provides the ability to regain quorum in the operating site if one site becomes unavailable, or in one
selected site if communication between the sites is lost. Such capability is necessary if volumes in the
management group reside on storage systems in both locations.
Management group in a single location with two storage systems
If you create a management group with only two storage systems, that management group is not a
fault-tolerant configuration. Using one manager provides no fault tolerance. Using two managers also
provides no fault tolerance, due to loss of quorum if one manager becomes unavailable. See
Managers
and quorum
on page 149 for more information.
Running two managers and adding a virtual manager to this management group provides the capability
of regaining quorum if one manager becomes unavailable.
Storage system maintenance using a virtual manager
A virtual manager can also be used during maintenance to prevent loss of quorum. Adding a virtual
manager to a management group enables you to start the virtual manager when you need to take a
storage system offline for maintenance.
Benefits of a virtual manager
Running a virtual manager supports disaster-tolerant configurations to support full-site failover. The
virtual manager ensures that, in the event of either a failure of a storage system running a manager,
or of communication breakdown between managers (as described in the two-site scenario), quorum
can be recovered and, hence, data remains accessible.
Requirements for using a virtual manager
It is critical to use a virtual manager correctly. A virtual manager is added to the management group,
but not started on a storage system until the management group experiences a failure and a loss of
Using specialized managers
170