Reference Guide

34 Preparing Your Systems for Clustering
13 Click Create Now .
The volume is mapped.
14 If you want to create another volume for the cluster server, select Create
Volume
and repeat step 2 through step 14. Otherwise, click Close to exit
the Wizard.
Optional Storage Features
Your Compellent Storage Center storage array may be configured to provide
optional features that can be used in conjunction with your cluster.
• Enterprise Manager : It is a separately-licensed application that manages
and monitors multiple Storage Center systems. It greatly simplifies
Remote Instant Replay.
• Data Progression: It leverages cost and performance differences between
storage tiers, allowing the maximum use of lower-cost drives for stored
data, while maintaining high performance drives for frequently-accessed
data.
• Data Instant Replay: A Replay is a point-in-time copy of one or more
volumes. Once an initial Replay of a volume is taken, subsequent Replays
preserve pointers to data that has changed since the previous Replay. This
minimizes the amount of storage space required to preserve periodic
copies of a volume.
• Remote Instant Replay: Remote Instant Replay replicates volumes to a
remote Storage Center and is an integral part of disaster recovery plan. It
offers two modes: synchronous and asynchronous.
– Synchronous replication: It makes sure that a write is successfully
written to the remote system before returning a Successful
Completion command to the server IO request. The Storage Center
does not acknowledge completion of the write-back to the server until
both the write IO to the local volume and the IO sent to the remote
system are complete. This indicates that both the replicating volume
and the replicated volume are fully synchronized and there is no data
loss in the event of a failure on the source system.
– Asynchronous replication: Asynchronous replication acknowledges a
write IO back to the server as soon as it is completed on the source
system. The write IO is also queued for delivery to the Remote system.