Volume Replicator Advisor (VRAdvisor) is a planning tool that helps you determine an optimum Volume Replicator (VVR) configuration. This document assumes that you understand the concepts of VVR.
This document provides information on installing and using this tool on different platforms. Wherever applicable, the information that is specific to a platform has been appropriately indicated. For Windows, note that the Veritas Volume Manager (VxVM) has been renamed to Symantec Storage Foundation for Windows (VSFW) from Release 4.1 onwards.
See the Symantec Storage Foundation and High Availability Solutions Tuning Guide for more information on tuning replication.
Planning is the key to successfully configuring VVR. To set up an optimum configuration, you must understand the components of VVR and their interactions with each other. In addition, you must consider the factors that are specific to your environment while planning your VVR configuration.
The important factors to consider while planning include:
Needs and constraints of the business
Mode of replication
These factors are dependent on each other and these dependencies must be considered during planning. For example, if your business requires that the data on the Secondary to be as up to date with the Primary as possible, you must choose synchronous mode and provide enough network bandwidth to handle the peak application write rate on the Primary. Or, if the available network bandwidth is less than the peak write rate of the application, you must choose asynchronous mode of replication. Also, the size of the Storage Replicator Log (SRL) must be able to handle the Secondary outages and network outages for the given application characteristics. VRAdvisor considers these dependencies and enables you to determine the parameters to suit your VVR environment.
VRAdvisor does the following:
Collects a sample of data that reflects the application characteristics.
Analyzes the sample of the application characteristic and calculates the size of the SRL and the network bandwidth required for replication.
Enables you to perform a What-if Analysis by varying the needs and constraints of your business, based on your future requirements.
Note that the replication log of VVR is referred to as SRL (Storage Replicator Log) on UNIX and as Replicator Log on Windows. The terms SRL and Replicator Log are used interchangeably in the document.