HP Serviceguard Extended Distance Cluster for Linux A.01.00 Release Notes, Second Edition, May 2008

HP Serviceguard Extended Distance Cluster for Linux Release Notes
What’s In this Version
Chapter 1 7
What’s In this Version
An extended distance cluster (also known as extended campus cluster) is
a Serviceguard cluster that has alternate nodes located in different data
centers separated by some distance. Using Linux MD, Serviceguard XDC
ensures high availability of data. Following are the key features of this
product:
• Supported in storage environments where the following Fibre
Channel based arrays are used for data storage:
— HP StorageWorks Modular Storage Array - MSA1000 and
MSA1500 families
— HP StorageWorks Enterprise Virtual Array (EVA) family
— HP StorageWorks XP family
• Supported in a 2 data center configuration.
• Supports 2 nodes with one node in each data center or 4 nodes with
two nodes in each data center. For information on requirements and
restrictions for a 4 node environment, see “Support for a 4-Node
Cluster” on page 11.
• Quorum Server must be configured in a third location for cluster
arbitration.
• Using MD, the disk sets are configured such that data written to one
disk or disk set is replicated or mirrored on the other disk or disk set
at the other site. As a result, if one disk set is lost, the data is still
accessible from the other disk set. The data in the other disk set is
always current and up-to-date, ensuring no data loss.
• HP Serviceguard A.11.16.07 or later is required for Extended
Distance Cluster. However, this product does not affect the
functioning of Serviceguard.
• You need to create the Multiple Device (MD) only once at the time of
configuration. From then onwards, you need to only activate or
deactivate the device.
• XDC requires that you configure persistent device names using udev
prior to configuring Software RAID.