Metrocluster with 3PAR Remote Copy for Linux Version B.01.00.00 Release Notes

of data availability. With synchronous operations, both the primary and secondary copies are
identical and concurrent at all times. Synchronous replication is appropriate when data currency
is critical while recovering a business application.
Support for Asynchronous Periodic Mode
Configure the 3PAR Remote Copy volume group in asynchronous periodic mode when you want
no impact on the response time of application.
In the asynchronous periodic mode, host writes are performed only on the primary storage array
and the host write is acknowledged as soon as the data is written into cache on the primary storage
array. The primary and backup volumes are resynchronized periodically when scheduled or when
resynchronization is manually initiated through the syncrcopy command. If an area of the volume
is written multiple times between two resynchronizations, then only the last write needs to be sent
to the other storage array. Therefore, when using Remote Copy in asynchronous periodic mode,
less data is transferred relative to the synchronous mode.
Support for Fully and Thinly Provisioned Virtual Volumes
Metrocluster with 3PAR Remote Copy for Linux version B.01.00.00 supports 3PAR Fully provisioned
Virtual Volumes and Thinly Provisioned Virtual Volumes (TPVVs). For TPVVs, all data and snapshot
space is allocated on demand from a Common Provisioning Group (CPG), and for fully provisioned
virtual volumes, only the snapshot space is allocated on demand from the CPG.
NOTE: Common Provisioning Group (CPG) is a user created pool of storage from which Virtual
Volumes are allocated.
As the volumes that draw from the CPG require additional storage, the system automatically creates
additional logical disks and adds them to the pool until the CPG reaches the user-defined allocation
limit that restricts its maximum size.
Support for Remote Copy configurations
The following Remote Copy configurations are supported in a Metrocluster environment:
• Bidirectional configuration : A bidirectional Remote Copy configuration is set up between two
arrays. Each storage system acts as the backup for the other storage system.
• N-to-1 configuration : In N-to-1 Remote Copy configuration, a maximum of 4 arrays can share
the same backup storage array. It supports only 3PAR Remote volume groups that are in
asynchronous periodic mode.
• 1-to-N configuration : In 1-to-N Remote Copy configuration, one primary array has a maximum
of 2 arrays as its backup. In a 1-to-N Configuration, only one pair of 3PAR storage systems
can have a bi-directional link.
For more information on each of these Remote Copy configurations, see the 3PAR Remote Copy
User Guide available at: http://h20000.www2.hp.com/bizsupport/TechSupport/
DocumentIndex.jsp?contentType=SupportManual&lang=en&cc=us&docIndexId=64179&
taskId=101&prodTypeId=18964&prodSeriesId=5044771.
Both N-to-1 and 1-to-N configuration can have unidirectional and bidirectional Remote Copy
configuration. However, the two arrays that are part of a Metrocluster must have a bidirectional
Remote Copy configuration between them.
NOTE: Synchronous Long Distance and Unidirectional Remote Copy configurations are not
supported in a Metrocluster.
Support for 3PAR Virtual Domains
Metrocluster with 3PAR Remote Copy for Linux version B.01.00.00 includes support for 3PAR
Virtual Domains. The HP 3PAR Virtual Domains facility enables fine grained privileges over system
objects such as volumes and hosts. Each domain can be dedicated to a specific application. A
What’s in this version 5