Veritas Storage Foundation 5.1 SP1 Cluster File System Installation Guide (5900-1510, April 2011)

■ Disassociate the SRL.
Preupgrade planning for Veritas Volume Replicator
Before installing or upgrading Veritas Volume Replicator (VVR):
■ Confirm that your system has enough free disk space to install VVR.
■ Make sure you have root permissions. You must have root permissions to
perform the install and upgrade procedures.
The following related documents are available:
Provides detailed explanation of VVR tunablesVeritas Volume Replicator
Planning and Tuning Guide
Describes how to change tunable valuesVeritas Volume Replicator
Administrator’s Guide
See the Getting Started Guide for more information on the documentation.
Planning an upgrade from the previous VVR version
If you plan to upgrade VVR from the previous VVR version, you can upgrade VVR
with reduced application downtime by upgrading the hosts at separate times.
While the Primary is being upgraded, the application can be migrated to the
Secondary, thus reducing downtime. The replication between the (upgraded)
Primary and the Secondary, which have different versions of VVR, will still
continue. This feature facilitates high availability even when the VVR upgrade is
not complete on both the sites. Symantec recommends that the Secondary hosts
be upgraded before the Primary host in the Replicated Data Set (RDS).
VVR supports replicating data between VVR 5.1 SP1 and VVR 5.0.1 or later.
Replicating between versions is intended to remove the restriction of upgrading
the Primary and Secondary at the same time. VVR can continue to replicate an
existing RDS with Replicated Volume Groups (RVGs) on the systems that you
want to upgrade. When the Primary and Secondary are at different versions, VVR
does not support changing the configuration with the vradmin command or
creating a new RDS.
Also, if you specify TCP as the network protocol, the VVR versions on the Primary
and Secondary determine whether the checksum is calculated. As shown in
Table 10-4, if either the Primary or Secondary are running a version of VVR prior
to 5.1 SP1, and you use the TCP protocol, VVR calculates the checksum for every
data packet it replicates. If the Primary and Secondary are at VVR 5.1 SP1, VVR
197Preparing to upgrade Veritas Storage Foundation Cluster File System
Preparing to upgrade