Building Disaster Recovery Serviceguard Solutions Using Metrocluster with Continuous Access XP P9000 for Linux B.01.00.00

The XP or P9000 RAID Manager allows you to run XP or P9000 Business Copy software and XP
or P9000 Continuous Access software commands from a host. Every execution of XP or P9000
RAID Manager is known as a RAID Manager instance.
RAID Manager instances running on the local nodes communicate with the RAID Manager instances
running on the remote nodes to get the status of the device group pair.
The following are the additional points to consideration when using XP or P9000 RAID Manager
in a Metrocluster environment:
• When adding a new volume to an existing device group, the new volume state is SMPL. Run
the paircreate command again on the device group. The disk array controller (DKC) is
smart enough to do the paircreate only on the new volume.
• If you change the LDEV number associated with a given target or LUN, you must restart all
the Raid Manager instances even though the Raid Manager configuration file is not modified.
• Any firmware update, cache expansion, or board change, requires a restart of all the Raid
Manager instances.
Command Device
A special volume on the disk array is designated as the command device. The command device
accepts Business Copy Software or Continuous Access Software control operations. The volume
designated as the command device is used only by XP RAID Manager and is blocked from other
user access.
Overview of solution for Metrocluster with Continuous Access XP P9000
for Linux
Overview of a Metrocluster configuration
A Metrocluster is configured with the nodes at Site1 and Site2. When Site1 and Site2 form a
Metrocluster, a third location is required where Quorum Server or arbitrator nodes must be
configured. There is a P9000/XP disk array at each site and they are connected to each other
through Continuous Access links.
An application is deployed in a Metrocluster by configuring it at both the sites. The sites are referred
either as primary or recovery site for an application, based on their role. Typically, the application
runs on the primary site. If there is a disaster in the primary site, the application automatically fails
over to the recovery site.
For each application, either synchronous or asynchronous or journal replication is configured to
replicate data between the two sites using Continuous Access device group. In a typical
configuration, more than one application is configured to run in a Metrocluster. Depending on the
application distribution in a Metrocluster environment, some applications can have Site 1 as its
primary site while some other applications can have Site 2 as its primary site.
Overview of solution for Metrocluster with Continuous Access XP P9000 for Linux 11