CLI Guide

Using The Remote Replication (Legacy)

Premium Feature

The Remote Replication (legacy) premium feature provides for online, real-time replication of data

between storage arrays over a remote distance. In the event of a disaster or a catastrophic failure on one

storage array, you can promote the second storage array to take over responsibility for computing

services. Remote Replication (legacy) is designed for extended storage environments in which the storage

arrays that are used for Remote Replication (legacy) are maintained at separate sites. Virtual disks on one

storage array are replicated to virtual disks on another storage array across a fabric SAN. Data transfers

can be synchronous or asynchronous. You choose the method when you set up the remote replicated

pair. The data transfers occur at Fibre Channel speeds to maintain data on the different storage arrays.

Because Remote Replication (legacy) is storage based, it does not require any server overhead or

application overhead.

You can use Remote Replication (legacy) for these functions:

Disaster recovery Remote Replication (legacy) lets you replicate data from one site to another site,

which provides an exact duplicate at the remote (secondary) site. If the primary site

fails, you can use replicated data at the remote site for failover and recovery. You

can then shift storage operations to the remote site for continued operation of all

of the services that are usually provided by the primary site.

Data vaulting and

data availability

Remote Replication (legacy) lets you send data off site where it can be protected.

You can then use the off-site copy for testing or to act as a source for a full backup

to avoid interrupting operations at the primary site.

Two-way data

protection

Remote Replication (legacy) provides the ability to have two storage arrays back up

each other by duplicating critical virtual disks on each storage array to virtual disks

on the other storage array. This action lets each storage array recover data from

the other storage array in the event of any service interruptions.

How Remote Replication (Legacy) Works

When you create a remote replicated pair, the remote replicated pair consists of a primary virtual disk on

a local storage array and a secondary virtual disk on a storage array at another site. A standard virtual disk

might only be included in one replicated virtual disk pair.

The primary virtual disk is the virtual disk that accepts host I/O activity and stores application data. When

the replication relationship is first created, data from the primary virtual disk is copied in its entirety to the

secondary virtual disk. This process is known as a full synchronization and is directed by the RAID

controller module owner of the primary virtual disk. During a full synchronization, the primary virtual disk

remains fully accessible for all normal I/O operations.