White Paper IMPROVING MICROSOFT EXCHANGE SERVER RECOVERY WITH EMC RECOVERPOINT Applied Technology Abstract This white paper outlines the challenges faced by Microsoft Exchange administrators in managing storage resources for their Exchange operations and describes how EMC RecoverPoint provides cost-effective business continuance and disaster recovery for enterprise applications such as Exchange. February 2011
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Table of Contents Executive summary... 4 Introduction... 4 Email challenges facing today s businesses... 4 Audience... 4 Data protection for Exchange... 5 Integration with EMC Replication Manager... 6 Integration with EMC Replication Enabler for Exchange... 6 Overview of the EMC RecoverPoint data protection technology... 7 Intelligent write splitting... 8 Array-based write splitting... 8 Fabric-based write splitting... 9 Host-based write splitting... 9 Using RecoverPoint to enhance Exchange operations... 10 Intelligent replication and recovery options... 10 Intelligent write splitting... 12 Investment protection... 13 Scalability... 13 Data availability... 13 Solution examples... 13 Solution 1: Improving Exchange availability through continuous data protection... 13 Solution 2: Long-distance Exchange replication with VSS-aware recovery... 14 Solution 3: Synchronous remote replication for Exchange without VSS... 16 Conclusion... 18 References... 19 Related EMC references... 19 Related Microsoft references... 19 3
Executive summary EMC RecoverPoint offers a variety of innovative and advanced ways to protect Microsoft Exchange. Implementing a disaster recovery and business continuance solution built around RecoverPoint will result in improvements in recovery point objectives (RPO) and recovery time objectives (RTO) and helps reduce your total cost of ownership (TCO) by reducing or eliminating backup windows along with their associated media usages. RecoverPoint fully supports Microsoft Exchange Server 2003, Microsoft Exchange Server 2007, and Microsoft Exchange Server 2010. Introduction Email challenges facing today s businesses Companies of all sizes and verticals consider email a business-critical application. Many of their core business processes rely on internal and external collaboration through email, and interruption of email also interrupts their commerce. Many corporations rely on Microsoft Exchange for their email and collaboration service, which has resulted in Exchange becoming a critical corporate asset and one that should be protected with the highest priority. More and more of these companies require zero or little data loss (RPO) for Exchange data yet, unfortunately, many of them do not have the budgets or resources to effectively protect their Exchange environment using existing data protection tools and applications. IDC Research estimates that the volume of email is growing at 300 percent a year with individual users generating an average of 5 MB of email content a day. The profusion of wireless email devices, such as the Research In Motion BlackBerry and the Apple iphone, is contributing to this growth. Businesses face challenges as message volumes continue to grow, and file attachments consume endless gigabytes of disk space. Protecting this data from disasters becomes more complex as backup windows shrink and recovery time has a direct business impact. The burden of constantly acquiring and managing new storage to keep up with growing needs is expensive and is compounded by the fact that for regulatory reasons, email messages must often be retained for longer periods of time. IT administrators spend as much as 15 percent of their time recovering email and up to 20 percent of their time backing up email systems. While traditional Exchange backup procedures help to minimize the business impact of an outage, the increased business-critical nature of Exchange requires that administrators seek out solutions that provide increased granularity for recovery points, while minimizing recovery times. Audience This white paper is targeted to corporate management and business decision-makers, including storage and server administrators, IT managers, and application engineers, as well as storage integrators, consultants, and distributors. 4
Data protection for Exchange EMC RecoverPoint is an enterprise-scale replication appliance designed to replicate and protect application data on heterogeneous SAN-attached servers and storage systems. When RecoverPoint is used, customers see dramatic improvements in application recovery with no data loss. Some customers are looking to move away from their current SAN infrastructure to a lower-cost storage platform. EMC offers the most trusted platform in the world for storing mission-critical data, such as Microsoft Exchange email data. RecoverPoint provides superior data protection for this mission-critical data when compared to traditional host and storage-system snapshots or disk-to-tape backup products. RecoverPoint provides full support for data replication and disaster recovery for Microsoft Exchange platforms. RecoverPoint allows for any-point-in-time recovery and enables the replication of data over any distance. Local replication utilizes RecoverPoint continuous data protection (CDP); remote replication such as to another site halfway around the globe utilizes RecoverPoint continuous remote replication (CRR); and both local and remote replication would use RecoverPoint concurrent local and remote (CLR) data protection. RecoverPoint supports replication of data that applications, such as Microsoft Exchange Server, are writing to volumes over Fibre Channel to local SAN-attached storage or over iscsi to CLARiiON storage. RecoverPoint utilizes a customer's existing storage infrastructure and integrates seamlessly with existing host applications and data storage subsystems. For long-distance asynchronous replication, RecoverPoint can use either a stretched fabric configuration or an existing TCP/IP infrastructure to send replicated data to the remote location. For synchronous remote replication, RecoverPoint relies on a stretched fabric configuration. It includes bandwidth compression, optimization, and acceleration technology that reduce the amount of data transferred by up to 10:1. This is ideal for asynchronous remote replication across low-bandwidth or longdistance WAN networks. RecoverPoint enables successful failover of operations to a secondary site in the event of disaster at the primary site. When used with RecoverPoint/Cluster Enabler, customers can utilize geographic failover with RecoverPoint for their Exchange 2003 and Exchange 2007 servers that utilize Microsoft cluster services. RecoverPoint can be used to roll back the target volumes to a consistent image at any point in time. The local copy can be rolled back to any point in time to undo individual write operations, while the remote copy can roll back to significant points in time that may be seconds or minutes apart. Additionally, RecoverPoint offers advanced integration capabilities for Exchange data protection, including support of the Microsoft Volume Shadow Copy Services (VSS) framework. With its unique architecture, powerful data recovery features, and business-driven approach, RecoverPoint offers advanced levels of data protection and enables business continuity to organizations running Microsoft Exchange applications. 5
Integration with EMC Replication Manager RecoverPoint is also integrated with EMC Replication Manager. Replication Manager s built-in application intelligence and automation enable users to schedule a VSS copy of Exchange both locally and remotely using RecoverPoint s replication technology. Replication Manager freezes the production Exchange database, requests a VSS copy, and flushes Exchange Server s cache to disk and creates a VSS bookmark for RecoverPoint and Replication Manager. Exchange is then thawed, all within the required VSS window of time. Once thawed, production resumes. Meanwhile the RecoverPoint VSS bookmark is captured in the local CDP journal as well as the remote CRR journal. Replication Manager can be used to automate tasks such as: Creating Exchange database application sets Creating and managing multiple site applications and consistent replicas of Exchange storage groups Running a full Exchange job to create a VSS bookmark, run the Microsoft Exchange utility eseutil, and then truncate the Exchange logs Running a copy Exchange job that creates a VSS bookmark Starting on-demand mount and dismount of Exchange storage groups Restoring Exchange storage groups from either local or remote bookmarks to the production Exchange server in seconds It is very easy to use Replication Manager s GUI interface to automate the restore of Exchange to an application-consistent point in time. Replication Manager will handle the restore locally via the RecoverPoint CDP replica or, if necessary, restore back to production with the RecoverPoint CRR Exchange replica. Integration with EMC Replication Enabler for Exchange Exchange Server 2010 introduced a concept called a Database Availability Group (DAG) to provide high availability for Exchange Mailbox Databases. A DAG is a group of Exchange 2010 mailbox servers that host a set of replicated databases to provide database-level protection from unplanned outages. A Native DAG deployment uses host-based network replication and a subset of Windows failover clustering technologies to provide high availability and site resilience. In Exchange Server 2010, DAGs replaced earlier Exchange and Windows failover clustering-based technologies used for HA and site resiliency, such as single copy clusters (SCC), continuous cluster replication (CCR), and standby continuous replication (SCR). In order to help address storage-based high availability and disaster recovery (DR) technologies, Microsoft Exchange Server 2010 includes an application programming interface (API) to integrate third-party replication solutions into the DAG framework. When enabled, third-party replication support will disable the native network-based 6
log shipping mechanism used by DAGs. Storage-based replication technologies can then be used to protect the Exchange database copies specified within the Exchange 2010 environment. EMC s implementation of the third-party replication API framework enhances this further, and also allows local shared clustering functionality that simplifies local failover/failback and reduces the amount of storage needed for HA. This solution also is approved by Microsoft and is fully supported as stated in the guidelines shown at http://technet.microsoft.com/en-us/library/dd638137.aspx. EMC Replication Enabler for Exchange integrates with the Exchange Server Third Party Replication API to enable both shared local storage as well as synchronously replicated storage with RecoverPoint as database copies within a DAG. The ability to utilize shared local storage as well as synchronously replicated remote copies helps to enable HA and site resiliency functionality similar to SCC and geographically dispersed cluster capabilities available with previous versions of Exchange. Using a RecoverPoint solution eases the strain on network bandwidth while preserving the scalability, reliability, and performance benefits of the storage array and provides incremental resync options, even in the case of DAG corruption. Overview of the EMC RecoverPoint data protection technology RecoverPoint is an advanced enterprise-class disaster recovery solution supporting heterogeneous storage and server environments. RecoverPoint provides bidirectional data replication across any distance, as well as local continuous data protection. RecoverPoint provides a full-featured replication and continuous data protection solution for all data, including that for an Exchange server. For remote replication, it utilizes either synchronous replication or small-aperture snapshots to protect the data from corruption, and guarantees recoverability with zero data loss. For local protection, it utilizes continuous data protection to track every write, protecting against any change of the data. Both local and remote replication enables recovery to any protected point in time. A RecoverPoint configuration enables local replication and remote replication for the same or different data. RecoverPoint is also bi-directional, which enables you to have production at both sites. The local and remote copy can be monitored and recovered using the RecoverPoint Management Application. These copies can be recovered to the same or different points in time as needed. The recovery of a copy does not impact the production server or the replication of its changes. RecoverPoint is an out-of-band solution, designed with the performance, reliability, and supportability required for enterprise applications. Running on a cluster of tightly coupled appliances, RecoverPoint s high-availability design ensures that the failure of a RecoverPoint appliance will not affect the protection processes and will be transparent to normal operations of the Exchange server. 7
Figure 1. RecoverPoint architecture The innovative technology of RecoverPoint supports flexible levels of policy-driven protection, without distance limitations or performance degradation. EMC s RecoverPoint technology offers a fine-grain recovery of application data, and reduces the time between recovery points to zero. Users have the capability to recover their data at any point in time, eliminating the need to invest in physical recovery of data damaged due to server outages, data corruption, software errors, or other common user errors. All of these capabilities help the customer achieve a dramatically lower TCO as compared to other host- or array-based replication solutions while offloading the compute power required to replicate from the production host or storage. Recovery testing is also made easier because of the ability to access the replicated data at the remote site for recovery or integrity testing purposes without interrupting the replication or the ongoing data center operations. Intelligent write splitting Any product that resides in the SAN and WAN junction has to be connected either inband (between host and storage) or out-of-band, with the aid of a host agent. All approaches can have drawbacks: The in-band approach has the potential of compromising SAN performance, integrity, and availability and can be very disruptive to deploy. The out-of-band deployment removes these drawbacks at the cost of requiring installation of a driver in the host, potentially adding complexity to the solution s deployment. RecoverPoint is an out-of-band technology that is flexible in where it places the driver that mirrors writes to the RecoverPoint appliances. This driver is called a write splitter, and it can reside in the VNX series or CLARiiON CX3 or CX4 storage arrays, in the SAN fabric, or on the production hosts. While a write splitter is required, it is only necessary to install the splitter(s) needed to support your configuration. Array-based write splitting RecoverPoint supports an array-based write splitter that runs inside each storage processor on VNX series or CLARiiON CX4 and CX3 UltraScale arrays. In this case, the storage processor carries out the write splitting; it does not occur on the host or in the fabric. The primary function of the array-based write splitter is to split application writes so that they are sent not only to their normally designated storage 8
volumes, but also to the RecoverPoint appliance. The array-based write splitter carries out this activity efficiently, with little impact to the storage processors performance, since the RecoverPoint appliance performs all CPU-intensive processing necessary for replication. The use of the splitter requires installation of the RecoverPoint enabler. Fabric-based write splitting 1 RecoverPoint is designed to support storage services APIs available on intelligent fabric switches, such as the Brocade Storage Application Services API for the Connectrix AP-7600B switch application platform. RecoverPoint also supports the Cisco SANTap API for the Cisco SSM or 18/4 blade installed in a Connectrix MDS 9000 intelligent switch. 2 Figure 2. Fabric splitting architecture RecoverPoint utilizes these fabric APIs from Brocade and Cisco for intelligent fabric write splitting. These fabric APIs enable RecoverPoint to support a variety of storage arrays for data replication with no host footprint and deliver high-performance bidirectional data replication between SANs across any distance, without any impact to host and array performance. With ample processing, and utilizing native SAN and WAN interfaces, RecoverPoint efficiently replicates data across heterogeneous storage arrays, server platforms, and networks without the need for protocol converters or edge connect devices. Host-based write splitting The RecoverPoint host-based write splitter driver (KDriver) is system software installed on all hosts that access protected volumes, that is, volumes being locally replicated using continuous data protection and/or remotely replicated using continuous remote replication. The primary function of the KDriver is to split application writes so that they are sent not only to their normally designated storage volumes, but also to the 1 RecoverPoint/SE does not support intelligent fabric splitters and host-based splitters on platforms other than Windows. 9
RecoverPoint appliance. The KDriver carries out this activity efficiently, with little perceptible impact on host performance, since the RecoverPoint appliance performs all CPU-intensive processing necessary for replication. Using RecoverPoint to enhance Exchange operations To support a highly scalable, highly available Exchange server, administrators must implement a highly available storage infrastructure. By utilizing RecoverPoint, server administrators will be able to improve the data recovery and availability of their Exchange server and dramatically improve their RTOs and RPOs. Microsoft Exchange Server is tightly coupled with the domain controller and uses the Active Directory (AD) service to provide authorization and authentication services for the Exchange servers and users. Disaster recovery for Exchange Server requires that the AD service be available at the production site as well as the disaster recovery site. It is recommended, therefore, that a domain controller running AD be configured on the remote site before beginning RecoverPoint replication. This facilitates better communication between the AD server and the Exchange server during the Exchange Server installation process. In addition, in the event of a total source-side failure during remote replication, it eliminates the potential service delay that results from the need to construct a new AD server at the target site. Intelligent replication and recovery options RecoverPoint supports local synchronous and remote synchronous or asynchronous replication between arrays. This replication is performed over the customer s existing SAN or IP infrastructure and benefits from intelligent data deduplication, data compression, and bandwidth optimization. Additionally the source and target arrays do not need to be identical, or even from the same manufacturer. This enables the use of lower-cost storage at the remote location. It also simplifies the resource requirements necessary when performing disaster recovery testing. Out of the box, RecoverPoint provides continuous protection with crash-consistent recovery for Exchange s log and database volumes. By using the Microsoft VSS API you can get full application-consistent recovery. Additionally, RecoverPoint can be used in combination with RecoverPoint/Cluster Enabler, to protect geographically dispersed Exchange Server 2003 or Exchange Server 2007 configurations. In addition to protecting Microsoft Exchange Server, RecoverPoint provides continuous local and remote replication for multiple hosts running other applications with crash- and application-consistent recovery. In such configurations, RecoverPoint can roll back the production volumes for all hosts back to the same point in time. RecoverPoint supports Microsoft Exchange Server 2010 for crash recovery, and using the Microsoft VSS API it supports Exchange 2010 for application recovery. RecoverPoint supports synchronous replication of Exchange Server 2010 DAGs using the EMC Replication Enabler for Microsoft Exchange Server 2010. The EMC Replication Enabler is a free software utility that integrates RecoverPoint and RecoverPoint/SE synchronous remote replication with the Exchange Server 2010 DAG architecture. RecoverPoint also supports replication of Exchange Server 2010 in a 10
virtualized environment. For additional information, please contact your EMC representative. RecoverPoint/Cluster Enabler is not supported with Exchange Server 2010. Instant recovery Continuous data protection gives administrators significant flexibility for Exchange recovery. Any Exchange image at any point in time can be instantly recovered and mounted in read/write mode on a recovery server. This image can be used for any purpose, such as Exchange single mailbox recovery or full storage group recovery. Application-aware bookmarks, such as the VSS bookmarks mentioned previously, give the administrator the flexibility to select the most appropriate image for recovery processing. In the event of an Exchange server failure the most current image can be quickly mounted by a standby Exchange server for operational recovery from server failure. Alternatively, a standby Exchange server for such uses as individual mailbox recovery can import the storage groups and log files from the snapshot image. Application-aware bookmarks improve recovery options EMC RecoverPoint offers seamless integration with Exchange that facilitates intelligent protection and recovery. Application, environmental, and user-created bookmarks are created during the replication process. These bookmarks can be used during recovery to dramatically reduce the application recovery time and help eliminate data loss. Microsoft Exchange Server supports the VSS API that enables RecoverPoint to integrate with Exchange. The VSS APIs are engineered to provide maximum reliability and performance, and support the full range of Exchange Server backup and restore functionality, including the full range of hot and snapshot backup capabilities. RecoverPoint provides a utility called KVSS that invokes the Microsoft VSS framework to prepare a VSS image. For full details on protecting Exchange with VSS, refer to the Replicating Microsoft Exchange Server with EMC RecoverPoint Technical Notes. Figure 3. Using VSS with RecoverPoint to protect Exchange 11
Simplified data migration EMC RecoverPoint can also be used to replicate data between local arrays connected on one or more storage area networks. This can be for array migration operations, such as replacing an array from one vendor with one from a different vendor. RecoverPoint will replicate the data across the SAN to another local array or remote array. When the replicas are in sync the original array can be disconnected or repurposed, with minimal application impact. Recovery from array and complete site failure With RecoverPoint, every time that Exchange writes to the local storage subsystem, the write is intercepted and copied in parallel to the local RecoverPoint appliance. In the event of an array or site failure, the appliance flushes its buffer to the secondary site, ensuring that write order is preserved. Using the RecoverPoint Management Application, it is simple for the administrator to bring up a consistent replica image for Exchange recovery processing. This enables quick recovery from the array and/or complete recovery from a site failure. Additionally, RecoverPoint/CE can be used to automate the failover and recovery of replicated data for Microsoft Cluster-aware applications. Protection from data corruption RecoverPoint efficiently maintains a transactional-consistent snapshot history at the remote site, allowing convenient rollback to any point in time, enabling quick recovery. This continuous protection eliminates the backup-window and the dataloss vulnerabilities inherent in traditional backup and snapshot systems. RecoverPoint supports multiple volumes in an Exchange Server configuration. Every single write to the Exchange storage groups and logs is replicated, preserving their write order. Using the time-stamped and application-aware bookmarks, administrators can recover the appropriate image just prior to the data corruption. This gives the administrator a powerful tool that minimizes the data loss and data recreation necessary for recovery from data corruption. Intelligent write splitting The EMC host-based write splitter driver (also known as a KDriver) is a lightweight module installed on every client that intercepts writes to protected volumes and sends a copy to RecoverPoint for further processing. As an alternative to having a splitter driver on each client, RecoverPoint can utilize write splitting inside a VNX series or CLARiiON CX3 or CX4 storage array, or write splitting that resides in intelligent Connectrix switches that use Brocade or Cisco technology. During intelligent write splitting, the Exchange I/O flows from the servers through the fabric-based or array-based write splitter to the storage volumes. When a write to a protected volume is detected by the splitter, a copy of the write is passed on to RecoverPoint. This happens transparently to the server and does not interrupt normal I/O operations. An advantage of this implementation is that it allows new servers to be protected by RecoverPoint without having to install an EMC splitter driver on each 12
client. This also allows for the installation of RecoverPoint without any application or server disruption. RecoverPoint can be deployed without the need to install host agents on the servers, which eliminates the need to schedule server maintenance and avoids application downtime. Investment protection RecoverPoint is an out-of-band solution that leverages the existing heterogeneous storage array resources available on the SAN. This allows the storage administrator to utilize any storage resource attached to the SAN for CDP, CRR, or CLR. Intelligent data deduplication, data compression, and bandwidth optimization technology allow for the use of existing IP network resources for remote replication, avoiding the need to purchase expensive FC/IP protocol converters, IP compression technology, or private, high-speed IP network connections. Scalability RecoverPoint has the ability support more servers or larger databases than would be possible within a single storage array using array-based replication. Additional RecoverPoint appliances can be added into the environment as the replication needs grow. Data availability Replication makes data available beyond the life of any single array by mirroring multiple copies of the data across arrays. If a physical array or volume should fail, the mirror is available to pick up the load. Additionally, data can be easily migrated from array to array in support of hardware upgrade cycles. Solution examples The following two solution examples show how RecoverPoint can be utilized to improve Exchange data protection and enhance recovery options. In the first example, a single site can be protected from storage hardware failures and data corruption by using local replication. In the second example, a remote site can be used both as a disaster recovery site for failover processing, as well as a business continuance site, allowing for remote backup and recovery processing. Solution 1: Improving Exchange availability through continuous data protection In this example, a four-node active/passive Exchange Cluster is used to protect against Exchange Server failure. RecoverPoint tracks all changes to the Exchange server and mirrors these changes to a local volume. This example also shows fabric write splitting using a Connectrix MDS-9000 with a Cisco SSM blade. The EMC hostbased write splitter driver or the array-based write splitter could have also been used to intercept the writes. In either configuration all of the writes are stored in a local CDP journal, which allows for recovery to any previous point in time. The continuous replication capability acts as a fail-safe in the event of local storage failures, while the CDP journal allows the administrator to roll back to a previous point in time, such as would be necessary to recovery from data corruption. The 13
administrator can quickly prepare a replica image that can be used to restart Exchange Server in the event of a local storage failure or can roll back the replica image to a previous point in time in the event of data corruption. Exchange Cluster Production RecoverPoint Production Copy Storage Groups and Logs Local Copy Protected Storage Groups and Logs Figure 4. Local protection for Exchange Local History Journal Tracks all changes Solution 2: Long-distance Exchange replication with VSS-aware recovery This example shows how the KVSS component for RecoverPoint can be used to enhance the recoverability of a Microsoft Exchange environment by providing a series of VSS-consistent Exchange images that complement the crash-consistent images automatically generated by RecoverPoint. In the production data center, Exchange is running in a four-way clustered configuration, with the Exchange storage group and Exchange log volumes residing on separate LUNs from a single array. These LUNs are synchronously replicated to a local copy. These LUNs are also synchronously replicated to a remote disaster recovery site, using a RecoverPoint policy that results in recover points spaced 15 minutes apart (an RPO of 15 minutes). The journal maintains the history of all recovery images, allowing the administrator to roll back the local and/or remote target volumes to any of these recovery points. Since RecoverPoint ensures that the dependent write-order consistency is maintained, each of these local and remote images represents a crash-consistent snapshot that can be mounted and used by an Exchange recovery server. When an image is selected for recovery, the local or remote target volumes are rolled back to the appropriate point in time, and then presented to the local or remote Exchange recovery server. After the database is restored, recovery is required to restart the database. The Exchange databases on the target volumes are in an inconsistent state, the same as if the Exchange server had crashed. Exchange soft recovery is a robust crash-recovery mechanism that "replays" the transaction logs to bring the database into the same state that the database would be in after a typical shutdown (a consistent state). An inconsistent database file must go through successful soft 14
recovery before it can be started again. Depending upon the size of the database this process can take minutes to hours. The Exchange server will automatically perform the soft recovery when it detects that the database is in this inconsistent state. To avoid Exchange s soft recovery, the administrator has also set up a local script that invokes the RecoverPoint KVSS utility, to create a VSS-compliant image once every three hours. These images are also stored in the journal but have a special VSS bookmark that is used to identify this image during recovery. When KVSS is invoked, it acts as a VSS requestor, much like a backup product does, and places Exchange into VSS backup mode. This causes Exchange to flush any data in memory to disk, and to mark the database as being in a consistent state. It then invokes the RecoverPoint VSS provider, which closes the current image, tags it with a special VSS bookmark, and then transfers the image to the remote site. Once at the remote site, the image is stored in the journal, and distributed to the target volumes. While this solution only documents remote replication, if RecoverPoint continuous local and remote data protection is used, the VSS bookmark will reside in both the local and remote journal, and either copy can be used for the VSS recovery process. When a VSS bookmark is selected for recovery, the volumes are rolled back to the appropriate point in time, and then presented to the Exchange recovery server. When Exchange examines the database, it finds that it is in a VSS-consistent state, so it will skip its soft recovery process, and immediately start the database. Production Exchange Cluster Capture Application Bookmarks Periodically put Exchange into VSS backup mode Test Recovery Select image, mount replicated volume to recovery server in read/write mode Recovery Exchange Recovery Servers RecoverPoint RecoverPoint WAN Production Copy Consistency group: storage groups and logs Local Copy Used for application recovery Local History Journal Tracks all changes Remote Copy Used for disaster recovery Remote History Tracks significant changes: PIT Image 121 VSS BOOKMARK 2 PIT Image 120 : PIT Image 61 VSS BOOKMARK 1 PIT Image 60 : PIT Image 1 History Journal Figure 5. RecoverPoint VSS-aware long-distance Exchange replication Once an image is at the disaster recovery site, it can be mounted read/write to a recovery server and used as the source for any process, such as a tape-based backup or for Exchange recovery processing. When read/write processing is complete, any writes can be discarded, or maintained for later use. An additional benefit of the remote journal is that it allows an image from a previous point in time to be quickly 15
restored and accessed without disrupting the replication between the production and disaster recovery sites. In the event of a production site failure, the remote replica can be used for Exchange storage or service recovery purposes. Additionally, since the image can be mounted as read/write, production could be started at the DR site, and when the production site is back online, the production site can be automatically resynchronized with the updated data from the DR site. Solution 3: Synchronous remote replication for Exchange without VSS Exchange is an application that benefits from synchronous remote replication when VSS is not utilized. This example shows how RecoverPoint synchronous remote replication can be used to enhance the recoverability of a Microsoft Exchange environment by providing a series of VSS-consistent Exchange images that complement the crash-consistent images automatically generated by RecoverPoint. In the production data center, an Exchange 2007 server is running in a four-way clustered configuration, with every change to the Exchange storage group and Exchange log volumes replicated locally for operational recovery and synchronously replicated over Fibre Channel to the disaster recovery site. All changes are stored in journals in the local and remote sites, enabling either copy to be used for operational or disaster recovery. The continuous replication capability acts as a fail-safe in the event of local site failure while the local copy allows the administrator to access the local copy by rolling it back to a previous point in time, such as would be necessary for recovery from data corruption. The administrator can quickly prepare a replica image that can be used to restart Exchange Server in the event of a local storage failure or can roll back the replica image to a previous point in time in the event of data corruption. This rollback capability can be performed at either location, without impact to other replicas, which is a benefit that RecoverPoint provides to the customer s site. 16
Figure 6. Synchronous local and remote replication of Exchange without VSS Since RecoverPoint ensures that the dependent write-order consistency is maintained, each of these local and remote images represents a crash-consistent snapshot that can be mounted and used by an Exchange recovery server. When an image is selected for recovery, the local or remote target volumes are rolled back to the appropriate point in time, and then presented to the local or remote Exchange recovery server. After the database is restored, recovery is required to restart the database. The Exchange databases on the target volumes are in an inconsistent state, though no replicated data was lost. The Exchange server will automatically perform a soft recovery when it detects that the database is in this inconsistent state. However, the soft recovery performed by Exchange will be performed with minimal impact to RTO. 17
Conclusion EMC offers a variety of innovative and advanced ways to manage your Exchange storage, reduce costs, and protect your data. Organizations implementing EMC RecoverPoint for Microsoft Exchange can expect to see the following benefits: Elimination of backup windows along with cost reductions by minimizing removable media usage Improvements in RPOs and RTOs with minimal application downtime during a disaster, or planned server or storage upgrades Use of the VSS framework when replicating Exchange ensures that the RecoverPoint images meet Microsoft s requirements for Exchange integrity and recoverability Full read/write access to all point-in-time snapshots, allowing the user to dial back in time and perform email searches, migration testing, or server recovery without impacting the performance of the production servers, or the replication process Out-of-band processing for replication ensures that Exchange Server performance is not impacted by RecoverPoint replication processes Rapid and simple replication for backup and recovery, automatically synchronized to an alternate location, and instantly accessible for disaster recovery or for recovery from logical corruption 18
References Related EMC references More information on EMC RecoverPoint can be found at the RecoverPoint page on EMC.com and in the following documents on the EMC Powerlink website: EMC RecoverPoint Family Overview A Detailed Review white paper Introduction to EMC RecoverPoint 3.4: New Features and Functions Applied Technology white paper EMC Solutions for a Virtualized Exchange 2007 Environment Using EMC RecoverPoint Reference Architecture Replicating Microsoft Exchange Server with EMC RecoverPoint Technical Notes (Powerlink only; P/N 300-004-904) EMC CLARiiON Storage Solutions: Microsoft Exchange 2007 - Best Practices Planning white paper Related Microsoft references Exchange Server 2007 Product Overview http://www.microsoft.com/exchange/2007/evaluation/features/ex_compare.ms px Features of Exchange Server 2007 http://www.microsoft.com/exchange/2007/evaluation/features/default.mspx#e UC Getting Started with Exchange Server 2007: Server Roles http://technet.microsoft.com/en-us/library/aa996031(exchg.65).aspx The Microsoft Exchange Team Blog http://msexchangeteam.com/ 19