Dell Power Solutions

STORAGEcentralized backup can offer significant benefits. Because data replicationallows organizations to perform the backup to tape only inthe regional data center, it can eliminate the need to deploy tapehardware and backup software in the remote locations that arebeing backed up—thereby helping to reduce the costs associatedwith implementing a remote backup solution. Thus, data replicationenables organizations to better utilize tape hardware, consolidatingthat investment in the data center. This approach enables tapebackups to be performed from a replicated copy in the regional datacenter, and branch office backups can be part of the data centerbackup schedule. As a result, the backup window can be muchlarger and more flexible than it is when using backup software tocopy branch office data directly to tape.This centralized approach can help reduce or eliminate theneed for trained backup administrators located at or supportingeach remote office. Moreover, it helps keep branch office personnelfocused on business—not backups. Because backups are conductedby trained administrators at the data center who adhere to correctdata protection and tape-handling methods that follow set IT policies,the risk of data loss is low. In addition, when copies of thebranch office Exchange data are stored off-site at the data center,this data can be protected from disasters such as fire, flood, or theftthat may occur at the remote location.Using LEGATO RepliStor for data replication can provide additionalbenefits. Because it transfers only the file operations for changes madeAn optimal approach tocentralized backup ofremote branch office datais to replicate data fromremote sites to the regionaldata center.to specific files, RepliStorhelps minimize network traffic.Data replication enablesdata transfers to be easilyand automatically restarted ifa network failure occurs, sodata transfers can be restartedfrom the point of the failurerather than from the beginningof a data set—a logicalstarting point for backup software.RepliStor is designed toautomatically and continuouslyreplicate data as the data is created, sending that data fromthe remote location to one or more secondary disk storage systems,local or remote. A second copy of production data can be created at aremote location, and this copy can always be up-to-date with the datain the regional site. This approach helps eliminate the backup windowfor the remote location and can avoid incurring backup-related CPUdrain on the Exchange servers at the branch office.Besides replicating data, RepliStor is designed to constantlymonitor Windows file-and-print services. Should a failure occur,RepliStor is designed to automatically recover those services ona second Windows server—enabling business users to continueworking while administrators find and fix the problem. As soon asthe failure occurs, RepliStor sends an alert notifying administratorsof the problem. However, because RepliStor is designed to provideautomated recovery, the on-call administrator does not have toimmediately address the problem. Administrators can continue withtheir current tasks, and when time permits, they can find and fixthe problem and test whether the system is working properly—allwhile business continues uninterrupted.Replication with LEGATO RepliStorLEGATO RepliStor is designed to provide real-time, asynchronousdata replication, which helps enable high availability and high reliabilityof Windows servers and Windows-based NAS without theuse of proprietary or specialized hardware. LEGATO RepliStor isdesigned to work with several popular data storage devices, includingDell/EMC CX series storage arrays as well as Windows StorageServer 2003–based NAS, including Dell PowerVault NAS servers.RepliStor provides one-to-one, one-to-many, and many-to-onebidirectional replication of data from one server or NAS deviceto another, over virtually any distance. When one server or NASdevice becomes unavailable, RepliStor is designed to automaticallyswitch file system services to the second NAS, preserving the endusers’ capability to access and use the data. LEGATO RepliStorcan be deployed in mixed environments, replicating data amongWindows Storage Server 2003 devices and server systems runningWindows 2000 Server and Windows Server 2003. This replicationcan be implemented over both local area network (LAN) andwide area network (WAN) connections, and offers both remoteinstallation and administration.At its core, LEGATO RepliStor provides a replication solutionthat is designed to copy files, directories, volumes, shares, and registrykeys from a source system (where data needs to be protected)to a target system or systems (where the data is then replicated).After the initial synchronization of the data, RepliStor mirrors thefile operations only for changes made to specific files, minimizingnetwork traffic. It then replays those file operations on the targetsystem to help ensure that both systems are in sync. Compressiontechnology plays an important role in the efficiency of the replicationas well, through reduced network overhead as compared touncompressed backup software transfers. Because RepliStor dataupdates are designed to be continuously and automatically replicatedas a background process between source and target systems,organizations can maintain multiple online copies of data withoutincurring additional administrative overhead. RepliStor deploymentand administration is facilitated by a powerful graphical user interface(GUI) that simplifies setup and implementation.Advanced features of granular, rules-based replication—such asfiltering and scheduling—allow flexibility in the selection of whatinformation RepliStor replicates and when the replication process76POWER SOLUTIONS Reprinted from Dell Power Solutions, February 2005. Copyright © 2005 Dell Inc. All rights reserved. February 2005