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Welcome to VMAX³ Remote Replication Fundamentals.Copyright 2015 EMC Corporation. All Rights Reserved. Published in the USA. EMC believes the information in thispublication is accurate as of its publication date. The information is subject to change without notice.THE INFORMATION IN THIS PUBLICATION IS PROVIDED “AS IS.” EMC CORPORATION MAKES NO REPRESENTATIONS ORWARRANTIES OF ANY KIND WITH RESPECT TO THE INFORMATION IN THIS PUBLICATION, AND SPECIFICALLY DISCLAIMSIMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Use, copying, and distribution of any EMC software described in this publication requires an applicable software license.The trademarks, logos, and service marks (collectively "Trademarks") appearing in this publication are the property of EMCCorporation and other parties. Nothing contained in this publication should be construed as granting any license or right touse any Trademark without the prior written permission of the party that owns the Trademark.Acartus, Access Logix, AdvantEdge, AlphaStor, ApplicationXtender, ArchiveXtender, Atmos, Authentica, AuthenticProblems, Automated Resource Manager, AutoStart, AutoSwap, AVALONidm, Avamar, Captiva, Catalog Solution, C-Clip,Celerra, Celerra Replicator, Centera, CenterStage, CentraStar, ClaimPack, ClaimsEditor, CLARiiON, ClientPak, CodebookCorrelation Technology, Common Information Model, Configuration Intelligence, Configuresoft, Connectrix, CopyCross,CopyPoint, Dantz, DatabaseXtender, Data Domain, Direct Matrix Architecture, DiskXtender, DiskXtender 2000, DocumentSciences, Documentum, elnput, E-Lab, EmailXaminer, EmailXtender , EMC2, EMC, EMC Centera, EMC ControlCenter, EMCLifeLine, EMC OnCourse, EMC Proven, EMC Snap, EMC SourceOne, EMC Storage Administrator, Enginuity, eRoom, EventExplorer, FarPoint, FirstPass, FLARE, FormWare, Geosynchrony, Global File Virtualization, Graphic Visualization,Greenplum, HighRoad, HomeBase, InfoMover, Infoscape, Infra, InputAccel, InputAccel Express, Invista, Ionix, ISIS, MaxRetriever, MediaStor, MirrorView, Navisphere, NetWorker, nLayers, OnAlert, OpenScale, PixTools, Powerlink, PowerPath,PowerSnap, QuickScan, Rainfinity, RepliCare, RepliStor, ResourcePak, Retrospect, RSA, the RSA logo, SafeLine, SANAdvisor, SAN Copy, SAN Manager, Smarts, SnapImage, SnapSure, SnapView, SRDF, StorageScope, SupportMate,SymmAPI, SymmEnabler, Symmetrix, Symmetrix DMX, Symmetrix VMAX, TimeFinder, UltraFlex, UltraPoint, UltraScale,Unisphere, VMAX, Vblock, Viewlets, Virtual Matrix, Virtual Matrix Architecture, Virtual Provisioning, VisualSAN, VisualSRM,Voyence, VPLEX, VSAM-Assist, WebXtender, xPression, xPresso, YottaYottaRevision Date:January 2015Revision Number: MR-1WP-VMAXRRFD.5977.0.0Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals1

This course provides an introduction of the VMAX³ Remote Replication. It includes an overview ofthe Remote Replication architecture, features, and functionality.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals2

This module focuses on VMAX³ Remote replication business requirements and benefits, theRemote Replication family of products, and typical use cases.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals3

The first thing to consider when selecting an information or data protection strategy is the sourceof outages.Less than one percent of outages are caused by natural disasters, such as hurricanes andearthquakes, or major business events, such as mergers and acquisitions.Unscheduled events account for most of the remaining fifteen percent of outages.The other fifteen percent or so, can be devastating if and when it occurs. Without preparation, anunplanned outage can severely impact the viability and profitability of a business.Planned downtime represented by normal housekeeping events account for approximately eightfive percent of all information outages. Planned downtime is often predictable, and manageable;so business continuity is assured even during regular maintenance windows eight-five percent ofthe time (or the majority of time).Replication technologies can also be applied to scheduled events, such as occasional migrationsand more frequently data re-purposing for decision support or test and development.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals4

SRDF is a designed solution for mission critical enterprise storage systems. It represents the mostreliable, scalable and trusted solution to ensure stock trading to continue to operate; airlinescontinue to the skies and Banks continue to give users seamless access to their money.For cloud scale deployments, SRDF provides a mechanism to maintain consistency across manystorage systems, so that recovery, the most important part of replication, is feasible no matterwhat the configuration.The correct remote replication solution can limit exposure to planned and unplanned downtime byenabling operations at remote sites. SRDF provides an organization with efficient data replicationtools to meet corporate or government standards, while still meeting Total Cost of Ownershiprequirements and lower RPO/RTO. SRDF offers data protection, and fast business restart in theevent of a disaster.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals5

SRDF is EMC’s Remote Replication technology that enables the remote mirroring of adata center with minimal impact to production application performance.The VMAX³ SRDF remote replication solution provides disaster recovery and data mobilitysolutions for the VMAX³ arrays. SRDF is EMC’s Remote Replication technology that enables theremote mirroring of data centers with minimal impact to production application performance.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals6

The copy process between the sites is accomplished independently without the host. There are nolimits to the distance between the source and the target copies. SRDF can integrate with otherproducts such as Microsoft Cluster Enable, VMware Site Recovery Manager (SRM) and withTimeFinder.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals7

This SRDF implementation example is a media and entertainment industry customer with a largecustomer base. The primary site servers use VMAX SRDF; remotely replicated 990 KM to a targetsite with another VMAX system. The approximate SRDF I/O traffic rates average about 25 MB/sec.The SRDF groups use SRDF/A mode for synchronization.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals8

The remote protection suite offers our industry leading SRDF synchronous and asynchronousmulti-site Disaster Recovery software. There are two VMAX3 Remote Replication Suite replicationlicenses available:Remote Replication Suite which includes: SRDF Family Block Multiple sites Replicator FileSRDF Registered which can be used for: Single remote replication Partial arrays replicationCopyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals9

This module focused on the VMAX³ Remote replication business benefits, Remote Replicationfamily of products and the typical use case.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals10

This module focuses on the VMAX³ Remote Replication architectural components and connectivityoptions, the topologies and dynamic operations.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals11

SRDF disaster recovery solutions use “active, remote” mirroring and dependent-write logic tocreate consistent copies of data. Dependent-write consistency ensures transactional consistencywhen the applications are restarted at the remote location.SRDF provides comprehensive business continuity and restart capabilities for planned andunplanned outages. This online, host-independent, mirrored data solution duplicates productionsite data on one or more physically separate target VMAX systems. What makes this technology aleader in the industry is its use of track tables. Track tables maintain the differential betweensource and target devices; track tables have a unique capability to send only changed informationat the track level. This allows SRDF to operate in several modes that are addressed later in thiscourse.SRDF compression is accomplished using an optional compression I/O module; compression canbe set at the SRDF group level.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals12

The SRDF family offers great flexibility in deployment depending on the business needs byoffering fully tested, integrated and flexible hardware, software and communication options.EMC offers native Gigabit Ethernet and Fibre channel capability for the VMAX³ series systems. TheFibre Channel or Gigabit Ethernet front-end I/O module is installed and configured in the VMAX³systems.The maximum number of SRDF supported groups and devices vary by Enginuity level; the tableillustrated shows the maximum limits.The connectivity protocol options include: Asynchronous Transfer Mode (ATM) Internet Protocol (IP) Dense Wavelength Division Multiplexing (DWDM) Coarse Wavelength Division Multiplexing (CWDM) T1/E1-T3/E3, and Synchronous Optical Networking (SONET)Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals13

SRDF groups define the relationships between the local SRDF instance and the correspondingremote SRDF instance.All SRDF devices must be assigned to an SRDF group. Each SRDF group communicates with itspartner SRDF group in another array across the SRDF links. RA ports are assigned to SRDFGroups with SRDF management software. All SRDF Devices must belong to a SRDF Group.VMAX3 and VMAX arrays will support up to 250 SRDF groups per system. When a VMAX3 isconnected to a VMAX, it will support 64 SRDF groups.All configured ports on a SRDF group will have the same topology (Switched Fabric or P2P).All configured ports on an RA have to use the same protocol (GIGE or FC).Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals14

At the primary site, a local host connects to a VMAX³ array. The device containing the productiondata to be remotely mirrored is called the primary (R1) device, also referred to as the sourcedevice.At the secondary site, a second host (optional) connects to the remote VMAX³ with the secondary(R2) device, also referred to as the target device, and contains the remotely mirrored data.The R1 and R2 devices appear as a mirror to the local device. They are not a physical mirror, butan entry on the track tables. The VMAX³ system’s R1 and R2 devices communicate through SRDFlinks. Under normal circumstances, the R1 device presents a Read-Write (RW) status to the hostthat accesses the R1. The R2 device presents Write-Disabled (WD) status to its host.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals15

SRDF supports regular synchronous and asynchronous SRDF, both between VMAX3 systems andbetween VMAX3 and VMAX2 systems. It also supports concurrent SRDF, replicating to two systemsconcurrently. In a two site configuration, synchronous, asynchronous and adaptive copy diskmodes are supported. A three site configuration will support concurrent modes of synchronous orasynchronous. Adaptive Copy Disk mode can be used in both two site and three siteconfigurations.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals16

Campus solution is limited to transmit data over short distances using VMAX systems and SANequipment; typically, the distance is smaller than 200 kilometers using channel extenders or longdistance fiber-optic cables.Extended Distance Wide Area Network provides SRDF connectivity over long distances usingtelecommunications networks, such as IP, SONET, or ATM.The Extended Distance Wide Area Network solution enables units to be at trans-oceanic or transcontinental distances for all types of directors. Typically, OC3, ATM, T3, and E3 lines, or IP areoffered by lease carriers.Fibre Channel SRDF can leverage write acceleration, sometimes referred to as Fast Write, aperformance enhancement feature offered by distance extension and/or switch products.When selecting the ideal business continuance solution, the selection is determined by thedistances separating the data centers, the Recovery Point Objective and Recovery Time Objective,and how well the applications tolerate network latency. Shorter distances reduce network latency,which allows using synchronous disk replication and data center mirroring. The SRDF solution canbe tailored to meet various Recovery Point Objectives/Recovery Time Objectives.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals17

There are three types of SRDF Link configurations:UnidirectionalBidirectional, andDual-directionalUnidirectional is a one-way mirror relationship.Bidirectional is a two-way mirror relationship where data moves in both directions on the SRDFlinks.Bidirectional configuration is only recommended in Campus mode due to the overhead associatedwith the change of direction.Dual-directional is an extended distance solution with two unidirectional SRDF RA groups, primaryand secondary, in each VMAX system.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals18

Dynamic SRDF provides the capability to change SRDF Groups and device pairings, as needed,without requiring a configuration change to be performed manually by EMC personnel. The twomain operations are: creating dynamic SRDF groups and device pairs. Only Dynamic SRDF issupported on VMAX³ arrays.A dynamic SRDF group represents a SRDF logical link between two VMAX³ arrays. After aDynamic SRDF group has been created, the SRDF device pairs can be added.An SRDF device is a logical device paired with another VMAX3 logical device that resides in asecond array; the arrays are connected by SRDF links.An SRDF device pair cannot include ProtectPoint devices. Dynamic SRDF enables the creation anddeletion of SRDF pairs while the VMAX system is in operation. Once established, the new SRDFpairs can be synchronized and managed in the same way as configured SRDF pairs.A requirement for Dynamic SRDF groups is ‘Switch’ connectivity, which is a SAN or GigE switchtopology.SRDF groups define the relationships between the local SRDF director/ports and thecorresponding remote VMAX³ SRDF director/ports. Any VMAX³ device that has been configured asan SRDF device must be assigned to an SRDF group.SRDF devices can dynamically swap “personality” between R1 and R2. After a personality swap,the R1 in the device pair becomes the R2 device and the R2 becomes the R1 device. SwappingR1/R2 personalities allows the application to be restarted at the remote site without interruptingreplication if an application fails at the production site. After a swap, the R2 side (now R1) cancontrol operations while being remotely mirrored at the primary (now R2) site. All volumescreated on a VMAX3 array will automatically be created as dynamic SRDF capable.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals19

This module covered Remote Replication architectural components, connectivity options andtopologies SRDF dynamic operations.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals20

This module focuses on the VMAX³ modes of Remote Replication, the new SRDF/A features andSRDF architectural elements.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals21

SRDF modes of operation address different service level requirements and determine how R1devices are remotely mirrored across the SRDF links. Also, how I/Os are processed and when thehost receives acknowledgment of a write operation relative to when the write is replicated.Synchronous Replication (SRDF/S) provides real-time mirroring of data between the sourceVMAX3 and the target VMAX3 systems.Data Mobility (SRDF/DM) transfers data from the source devices to the remote devices withoutwaiting for an acknowledgment, using Adaptive Copy mode.Asynchronous Replication (SRDF/A) places host writes into ‘cycles’ or ‘chunks’ and then transfersan entire chunk to the target system.SRDF/CG - SRDF consistency groups preserve the dependent-write consistency of devices within agroup by monitoring data propagation from source devices to their corresponding target devices.If consistency is enabled, and SRDF detects any write I/O to a R1 device that cannotcommunicate with its R2 device, SRDF suspends the remote mirroring for all devices in theconsistency group before completing the intercepted I/O and returning control to the application.These operational modes can be changed dynamically using EMC software, the operationalmethod can be specified on a per device basis or as a device group.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals22

SRDF/Cluster Enabler (CE) allows combination with the features of Microsoft Failover Clusterintegration.SRDF/AR is an automated remote replication solution that uses both SRDF and TimeFinder toprovide a periodic asynchronous remote replication of a re-startable data image for UNIX andWindows environments. It is the least expensive of the listed solutions, because it can beconfigured to run on lower bandwidth networks than the other solutions, it offers a typical RPO ofhours.Concurrent SRDF permits the maintenance of two data copies. Usually, one copy running SRDF/Sis maintained at a nearby location and offers zero data loss if the primary site fails. The secondcopy operating in SRDF/A mode offers an out of region recovery site with an RPO of seconds tominutes. Cascaded SRDF three site configuration uses bunker site and combines Synchronous andAsynchronous modes. Data from a primary site is synchronously replicated to a secondarysite, and then asynchronously replicated to a tertiary site. The major benefit provided with a“cascading” configuration is its inherent capability to continue replicating from the secondarysite to the tertiary sites in the event that the primary site goes down.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals23

SRDF Synchronous Mode is primarily used in SRDF campus environments. In this mode ofoperation, the VMAX³ maintains a real-time mirror image of the data of the remotely mirroreddevices.Data on the source (R1) target (R2) devices are always fully synchronized at the completion of anI/O sequence through a first-in, first-out queue (FIFO) model. All data movement is at the blocklevel with synchronized mirroring.Synchronous SRDF writes from the host to the primary and do not finish until they areacknowledged at the primary VMAX³ and the write data is resident in the secondary VMAX³system's cache. This means that the logical device is busy at the primary host including readfollowing-write operations throughout the SRDF operation.Copyright 2015 EMC Corporation. All rights reserved.VMAX³ Remote Replication Fundamentals24

SRDF Adaptive copy modes facilitate data sharing and migration. These modes allow the primaryand secondary devices to be more than one I/O out of synchronization. The maximum number ofI/Os that the R2 can be out of synchronization is known as the maximum skew value. The defaultvalue is equal to the entire logical device. The transfer steps are illustrated here.SRDF Adaptive Copy Disk Mode is designed for bulk data transfer. Host write tasks accumulate onthe primary device as invalid tracks rather than in global memory. A backgroun