Protecting heterogeneous Dell storage environments using AppAssure Backup and Recovery

Transcription

1 TECHNICAL REPORT: Performance Study Protecting heterogeneous Dell storage environments using AppAssure Backup and Recovery ABSTRACT Data migration and replication between data centers with heterogeneous storage environment can be not only slow and expensive but also excessively complex. To heighten business continuity, many enterprises seek migration and disaster recovery solutions that are optimized for diverse computing environments. Dell EqualLogic and Compellent storage systems, along with Dell AppAssure software, work together to enable rapid replication of physical and virtual workloads. This technical report describes a solution that leverages Dell AppAssure s non-disruptive snapshot technology to move data efficiently between datacenters with minimal impact on performance. V1.0

2 Copyright 2013 Dell Inc. All Rights Reserved. EqualLogic is a registered trademark of Dell Inc. Dell is a trademark of Dell Inc. All trademarks and registered trademarks mentioned herein are the property of their respective owners. Information in this document is subject to change without notice. Dell Inc. will not be held liable for technical or editorial errors or omissions contained herein. The information in this document is subject to change. Reproduction in any manner whatsoever without the written permission of Dell is strictly prohibited. October 2013

3 Preface Dell EqualLogic PS Series arrays are easy to use and optimize resources and simplify operations by automating many performance enhancement and network load balancing tasks. Additionally, PS Series arrays offer all-inclusive array management software, host software, and firmware updates with no additional license fees. Dell Compellent arrays are self-optimized, intelligent storage for dynamic data centers. With advanced storage software, Dell Compellent helps customers efficiently meet performance and capacity requirements through automated intelligent data placement, keeping hot data on high performance drives and cold data on large capacity optimized drives. Dell AppAssure backup, replication and recovery software is a robust disaster recovery solution designed to keep up with the needs of today s business. AppAssure is built for IT professionals who need a powerful, affordable and easyto-use backup, replication, and recovery solution that provides protection for servers and business-critical applications like Microsoft Exchange, Microsoft SQL Server, and Microsoft SharePoint. Not only can AppAssure protect critical applications, it can do so continuously up to 288 times per day via a single web-based management console. Audience The information in this guide is intended for storage administrators of Dell EqualLogic iscsi arrays, Dell Compellent Storage Center, and Dell AppAssure backup, replication recovery technology. Related Documentation For detailed information about Dell storage and software products visit: and Dell Online Services You can learn about Dell products and services from the following web based resources: 1. Visit or the URL specified in any Dell product information. 2. Use the locale menu or click on the link that specifies your country or region. Dell Storage Solutions To learn more about Dell products and new releases being planned, visit the Dell TechCenter site: Here you can also find articles, demos, online discussions, technical documentation on infrastructure and application best practices, and more details about the benefits of our product family. For an updated Dell EqualLogic compatibility list please visit the following URL: kc.compellent.com

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5 TABLE OF CONTENTS Revision Information... iii Executive Summary... 1 Introduction... 1 Objective... 2 Solution Components... 2 EqualLogic PS Series Storage Array... 2 Compellent Storage Center... 2 AppAssure and AppAssure Replication... 2 Test configuration and tools... 3 Testing Overview... 4 Test Enviornment... 6 Test Process... 7 Results and Analysis... 8 Bandwidth effects... 9 Latency effects Best Practice and Recommendations Conclusion... 12

6 REVISION INFORMATION The following table describes the release history of this Technical Report. Report Date Document Revision 1.0 October 2013 Initial Release The following table shows the software and firmware used for the preparation of this Technical Report. Vendor Model Software Revision Dell TM Dell Compellent Dell TM Dell AppAssure Dell Dell Equallogic PS4100X Dell TM Dell EqualLogic PS6100XV Dell TM Dell EqualLogic SAN Headquarters Dell TM Force 10 S-Series S60 Switches OS Version: 1.0 Dell TM HIT Kit V4.0 Microsoft Windows Enterprise Server Microsoft SQL Server 2008, 64-bit SP1 Application Software Version: Microsoft Windows Enterprise Server 2008 R2, 64-bit SP1 Microsoft iscsi Initiator v Microsoft Perfmon VMware VMware vsphere 5.0 Update 1 iii

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8 EXECUTIVE SUMMARY Many businesses today are challenged with consolidating their globally dispersed data centers with massive amounts of data and limited resources. Adding to this challenge is the exponential growth in the volume, variety and velocity of data that today s enterprises are required to manage. Accordingly, reliable data protection has become more important than ever before. Business continuity and disaster recovery (BC/DR) requirements drive the need for data center to data center storage replication and virtual machine migration capabilities. The mix of heterogeneous hardware and software found in many enterprises is a natural result of expansion, whether through organic growth, mergers, or acquisitions. Additionally, remote offices, test facilities and quality assurance labs may choose to deploy systems that differ from those in their corporate data center. These diverse computing environments are spurring IT groups to leverage novel ways of facilitating interoperability and streamlining data sharing. Many organizations have tried to piece together data protection solutions from multiple vendors to help ensure business continuity. In these mixed environments, critical business information often resides across a variety of file systems and databases within the enterprise. Frequently, portions of the data contained in each silo are redundant but not necessarily in sync across platforms. For positive decision making outcomes, organizations must skillfully manage and protect their data so that it is consistent, timely and accurate. Both data migration and replication are important activities that consume significant budget and labor. The combination of the resources consumed by and frequency of a data migration results in migration taking a significant amount of the IT budget. As storage infrastructures become diverse and more complex, data migrations are becoming more complex and labor intensive. Organizations must begin managing this growing portion of their IT budgets more effectively. Moreover, as enterprises consolidate their IT infrastructures through virtualization, data protection and disaster recovery have become increasingly important to maintain business continuity. However, explosive data growth and intensified IT complexity complicate the data protection landscape. At the same time, IT professionals are being pressed to meet increasingly aggressive recovery time objectives (RTOs) and recovery point objectives (RPOs). The number of applications and the amount of data considered mission critical within today's business environments are at an all-time high. Organizations of all sizes demand the highest levels of availability for their business applications to avoid lost revenue and reduced productivity. In short, the availability and the protection of business applications have become ever more critical. As IT organizations evaluate availability requirements for today's critical applications, they find achieving these availability objectives via traditional methods to be a daunting task. This technical report describes an end-to-end, tested and validated Dell solution for designing data migration and disaster recovery in a heterogeneous IT environment that includes both Dell Compellent and Dell EqualLogic storage arrays using the Dell AppAssure replication feature. This report provides performance data demonstrating that in environment s with low to high amounts of latency AppAssure can still be used reliably for data migration. INTRODUCTION This whitepaper outlines the planning and performance considerations for data migration and disaster recovery between Dell EqualLogic and Dell Compellent storage arrays using AppAssure snapshots and replication. Using the AppAssure replication feature, organizations that wish to operate a mix of Dell storage can easily migrate and replicate data from an EqualLogic SAN to a Dell Compellent SAN or vice versa. AppAssure enables organizations to quickly recover from a site-wide disaster by 1

9 recovering block and file data stored on Dell SANs across a WAN. In situations that call for data replication between like-to-like platforms, such as among EqualLogic SANs or among Dell Compellent SANs, administrators can use the built-in data protection capabilities of each respective platform. OBJECTIVE This technical report describes a tested and validated solution for designing a data migration and disaster recovery between Dell EqualLogic storage and Dell Compellent storage using Dell AppAssure software. This solution helps administrators eliminate backup windows, ensure recoverability and availability, and achieve near-zero RTOs and granular RPOs. Dell AppAssure software and Dell Compellent and EqualLogic storage work well together to maximize storage efficiency, boost IT agility and enhance business resiliency. SOLUTION COMPONENTS EqualLogic PS Series Storage Array The EqualLogic PS Series storage solution provides consolidated network storage in a selfmanaging, iscsi storage area network (SAN). The peer storage architecture used in the PS Series delivers high performance, availability, and scalability with an all-inclusive software model. The architecture allows all of the arrays to share resources, distribute workloads, and provide the highest levels of performance while reducing complexity and cost. Compellent Storage Center The Compellent Storage Center SAN is an all-in-one storage array that allows organizations to actively manage data at a highly granular level using built-in intelligence and automation. This ultra-efficient, easy-to-manage storage solution optimizes drive utilization, dynamically moves data between storage tiers and RAID levels, continuously protects data against downtime and disaster, scales on demand, and quickly adapts to ever-changing business needs. Storage Center enables organizations to cut the time, cost and risk of managing enterprise storage today and in the future. AppAssure and Replication Dell AppAssure delivers near continuous data protection to mission critical applications while providing minimal CPU impact to the protected host. Features such as Recovery Assure, Live Recovery and Virtual Standby are provided by a dedicated backup server known as the AppAssure Core. This Core ensures that in the event of a disaster, administrators can meet the most stringent SLA s with ease. The benefits of AppAssure are realized via Smart Agents that provide snapshots up to every five minutes while consuming no more than 1-3% CPU usage on protected systems. AppAssure provides a simple set-it and forget-it replication process that keeps snapshots upto-date in two locations. With just a few simple configuration steps, it can be assured that Dell AppAssure will keep the data safe in case of hardware failure, system corruption or a total site failure. The only requirement to setup AppAssure replication is a secondary Core as a replication target, which can be located in a local data center, a remote Disaster Recovery Site (DRS), or even in the cloud. AppAssure is both hardware and storage agnostic, allowing it to use any combination of storage at both the source and target locations. 2

10 TEST CONFIGURATION AND TOOLS Dell Lab solutions are designed to reflect and validate real-world deployments. Figure 1 depicts the physical architecture of the solution described in this whitepaper. Figure 1: Solution architecture Using Dell AppAssure software to migrate and replicate data between Dell Compellent and Dell EqualLogic storage. This solution demonstrates data migration and disaster recovery capabilities between Dell storage platforms. This configuration could represent an environment where an organization wants to migrate data from an application running on EqualLogic storage to Compellent storage systems (see figure 1). To migrate data, the administrator would load AppAssure software on two Windows Server 2012 Dell PowerEdge servers to create a source Core server at the primary site and a target Core server at the secondary site. Dell AppAssure Smart Agents are then installed on a virtual machine running Microsoft SQL Server database software. Key design details of the test system configuration shown in Figure 1 include: The test configuration consisted of a designated primary site and secondary site, although all of the hardware was physically located in the same datacenter. One EqualLogic PS6100XV array and one PS4100X array in a single group on the primary site. The PS6100XV array had 24 x 146GB 15K RPM SAS disk drives in RAID 50 configuration, and the PS4100X has 24x900GB 10K SAS disk in RAID 50 configuration, which hosted SQL Server database volumes and AppAssure repository volumes. Repository volumes are SAN-based storage containers designated for storing backups. Two SC8000 controllers, with 24 disk drives; 4x400GB SLCSSD, 12x300GB 15K SAS, and 12x1TB 7.2K NL-SAS disk with Compellent. One AppAssure Core server with 64 GB of RAM. 2 X Intel Xeon E CPU and 1TB repository at the primary site. The AppAssure repository resides on a 1TB volume located on EqualLogic storage. Protected server VM at the primary site has AppAssure Smart Agent and Microsoft SQL Server 2012 installed. One AppAssure Core server with 128 GB of Ram, 2 X Intel Xeon E CPU and 1TB repository at the secondary site. The AppAssure repository resides on a 1 TB volume located on Compellent storage. The AppAssure Core is performing a virtual standby of 3

11 the protected SQL Server to a vsphere 5 server every 60 minutes. The created virtual standby is configured to use the same amount of RAM as the source VM and uses a thin provisioned disk. The SAN switches consisted of two Dell PowerConnect 6248 switches, configured per the Dell best practices. Redundant connection paths were created from each array controller to each switch in the stack. Two R720 Dell PowerEdge servers were used to host SQL Server VMs on primary and secondary site. Each of these VMs (SQL DB) had SQL Server 2012 Enterprise Edition installed on Windows Server 2008 R2 SP1 Enterprise Edition. Each virtual machine that hosted SQL Server 2012 was configured to use four virtual CPUs and 34 GB of reserved memory. 32 GB was allocated to the SQL Server by specifying the maximum server memory setting in SQL Server Management Studio. VMWare vsphere 5 was installed on the servers that were used to deploy the SQL Server databases. The server disks were configured as RAID 50, and the guest virtual machine OS disk partitions were also hosted within the virtual machine file system on the disks. The primary and secondary sites were connected through an Apposite Technologies Netropy 10G WAN emulator. This allowed us to throttle bandwidth and add impairments such as latency, etc., to the WAN connection to simulate the various speeds and conditions that one might encounter with a WAN. TESTING OVERVIEW In this test, we established SQL database replication between Dell EqualLogic storage and Dell Compellent storage using Dell AppAssure software. During this testing, the impact of various bandwidth limitations and latency settings on AppAssure replication was studied. Based on these observations, best practices for AppAssure replication between EqualLogic and Compellent storage were developed. This paper addresses two cases in which Dell EqualLogic and Dell Compellent customers may choose to utilize AppAssure The first use case is to migrate data from disparate storage platforms to one common storage platform. When leveraging AppAssure this can be done without any disruption. The second use case is to provide WAN optimized replication to organizations with heterogeneous Dell Storage platforms at the data center. In this case, remote backups are compressed, deduplicated and even encrypted before being sent over a WAN link to the corporate data center. After replication, a Virtual Standby of remote office machines can be created at the data center to safeguard against long periods of downtime should a remote site experience a failure. The following is the procedure of performing data migration and data replication from an existing primary site using Dell EqualLogic storage to a secondary location that hosts Dell Compellent storage (see figure 1). In order to perform a data migration, the following steps were performed Installed AppAssure software on Windows-based Dell PowerEdge servers to create a source core server at the primary site and a target core server at the secondary site. Configured AppAssure repository volumes on the EqualLogic SAN at the primary site and the Compellent SAN at the disaster recovery site. 4

12 Note: Repository volumes for AppAssure software are SAN-based storage containers designated for storing backups. The repository pre-allocates the storage required for housing the snapshots and their metadata. All data housed in the repository is deduplicated, compressed and optionally encrypted. Installed the AppAssure smart agent on the SQL Server followed by a reboot of the SQL server. Configured replication of the SQL Server data that resided on EqualLogic storage from the primary site to the secondary site where it will use Compellent storage. Configured snapshots of the SQL server to occur every 5 minutes and manually initialized a base image. Note that with AppAssure, all subsequent snapshots are incremental and at block level. Configured the replicated SQL Server VM for virtual standby at the secondary site. Here the VM is created on avsphere 5 server using Compellent storage for its data store. This virtual standby is an up to date copy of SQL Server VM ready to go when there s a failure at the primary site The below procedure is one that can be utilized with AppAssure Simplifying disaster recovery In the event of disaster or a comprehensive outage, the administrator can fail over to the secondary site with just a few clicks of button. At the secondary site a virtual standby of the replicated SQL Server VM can be powered on utilizing the same hostname, IP configuration, CPU and RAM as the original VM. The powered on host is automatically protected by AppAssure ensuring that snapshots of the failed over VM are taken at the same frequency as its original source VM. Note: Virtual Standby allows for the continual export of AppAssure snapshots to either VMware Workstation, vsphere or Microsoft Hyper-V server. The virtual standby is a configurable replica a chosen production machine that is ready to go at any moment. This process takes place after each snapshot of selected physical or virtual machines, updating the existing virtual copy with new changed blocks each time. After the primary site has been restored and brought online the target Core server can failback protection to the primary EqualLogic storage. With just a simple process the changes that occurred while the primary site was down can be replicated back to the primary site, the primary SQL Server can be updated with changes from the secondary site and its protection can resume its normal frequency. 5

13 Note: Integrated global deduplication and compression reduces the size of the incremental snapshots as they are ingested, greatly minimizing backup storage requirements. AppAssure asynchronously transmits the deduplicated and compressed snapshots to the target core server and the Compellent SAN at the secondary location, resulting in optimal bandwidth utilization between the two sites. TEST ENVIORNMENT Primary Storage Configuration Configuration Parameters EqualLogic SAN One PS4100X (2.5", K SAS drives,900 GB) One PS6100XV (2.5, K SAS drives, 146 GB) RAID type RAID 50 SQL DB volume Configuration SQL DB Files- Volume size Primary Data File (.mdf) 35GB Log File (.ldf)-10 GB TempDB-10GB AppAssure repository volume configuration AppAssure repository volume 1 TB Table 1: Primary Storage configuration Secondary Storage Configuration Configuration Parameters Compellent Storage Center RAID type Two SC8000 Controllers (2.5 4xSLCSSD 400GB, 15K 300GB, and 12x7.2k 1TB) RAID 10 for SLCSSD, RAID 5 for 15K, and RAID 6 for 7.2 K NL-SAS SQL DB volume Configuration SQL DB Files- Volume size Primary Data File (.mdf) 30GB Log File (.ldf)-10 GB TempDB-10GB AppAssure repository volume configuration AppAssure repository volume 1 TB, Thin Provisioned Table 2: Secondary Storage configuration 6

14 REPLICATION PROCESS AppAssure replication is easy to configure and is ideal for those looking to replicate long distances. AppAssure can replicate entire datacenters cross-campus, cross-country without being highly impacted by network latency.. Steps for replication 1. Create a 1TB AppAssure repository located on the EqualLogic SAN. Note: Normally it is best practice to place the AppAssure metadata and data paths on separate volumes but this is not necessary when using EqualLogic storage. This is due to EqualLogic s virtualized storage that always optimizes performance. 2. Connect to vcenter via the AppAssure interface and protect SQL Server-001 by deploying an AppAssure Smart Agent. 3. Configure Outgoing replication for SQL-001 is setup from the primary site to the secondary site. The VM is configured to replicate with a default priority of 5 and is triggered when a new snapshot of SQL-001 is ingested into the primary AppAssure Core. 7

15 4. A base image (full backup) of SQL-001 is forced using the Force Snapsot option at the primary site. Upon completion of the base image AppAssure automaticity replicates to the secondary site. The replication from the primary site to the secondary site is compressed and deduplicated to reduce the needed bandwidth and replication time. 5. After the base image is taken and replicated, snapshots (incrementals) then occur on a regular basis and are replicated to the secondary site. 6. Using AppAssure s RecoveryAssure technology, a SQL attachability check was initiated after the base image and snapshot to ensure the integrity of the database recovery point. This check normally happens every night at a user defined time but can manually be triggered at any time. The check works by attaching the protected SQL database to an instance of SQL located on the AppAssure Core server to ensure that it is functional. This is done along with a checksum of entire backup. RESULTS AND ANALYSIS Dell Labs conducted testing to qualify AppAssure replication between Dell Compellent and Dell EqualLogic storage platforms. During this testing, the impact of various bandwidth limitations and latency settings on replication performance was studied. To establish a reference baseline, AppAssure replication performance was measured using a direct connection between the two AppAssure Core servers. Once the baseline performance was measured, we used the WAN emulator to simulate speeds of 1Gb, OC3 (155 Mbps), and T3 (45 Mbps) networks. Latency of 5, 20 and 80 milliseconds each way was added to the testing to determine performance degradation due to latency. 8

16 Note: 5ms is a fairly low latency which simulates primary storage arrays on the same campus/data center as the secondary storage platform that may be behind a few routers. 20 milliseconds of latency is equivalent to a WAN link between Austin, TX and Santa Clara, CA, while 80 milliseconds is equivalent to a WAN connection between Santa Clara, CA and New York City, NY. The throughput was measured in the AppAssure management interface and was converted from megabytes per second (MBps) to megabits per second (Mbps) for easier comparison to standard WAN speeds. For these tests, the Apposite Technologies Netropy 10G WAN emulator was used to simulate WAN connection. The Netropy 10G uses dedicated packet processors to ensure precision and repeatability. Besides throttling bandwidth, it can also inject latency, jitter, and packet loss. This was used to simulate the behavior of several different kinds of SAN and WAN links between the two sites. We configured the Netropy 10G to participate in flow control and configured a queue size (analogous to a router s internal buffer) of 1024 KB (or 1 MB). Actual WAN links can vary in speed or guaranteed bandwidth from provider to provider. For each test case, we used one of the values (1 Gb, OC3 (155 Mbps), or T3 (45 Mbps)) with the WAN emulator to simulate the bandwidth of a WAN or SAN connection between AppAssure replication partners. Next, at 1 GB bandwidth, latency (each direction) of 5, 20, and 80ms was introduced to simulate distance between the two datacenters. The results of each combination were recorded so that they could be compared to the previous runs where there was no additional latency. Before each replication, the replication relationship between the two AppAssure Core servers was severed. This process consisted of terminating the incoming replication job to the remote Core server as well as deleting all recovery points of the SQL VM on the secondary Core. This was done to ensure that the primary AppAssure Core has to send all of the already compressed and deduplicated blocks of the SQL VM from the local repository to the repository of the secondary Core server. By doing this, we assure that there are no duplicate blocks of data on the secondary Core server that may affect the speed and size of the data to be replicated. This results in a larger amount of data being sent over the WAN that normally would only been seen during the initial replication of a protected machine and not during the subsequent snapshot replication. Had there been snapshots of similar machines located in the secondary Core s repository we would have been able to further mitigate the amount of data sent over the WAN. Furthermore, subsequent snapshots (incremental s) would be much smaller in most cases due to AppAssure s changed block tracking and take as little as a few seconds to compete. It is also important to note that AppAssure has the ability to seed the initial full back up onto an external drive to simplify the process of replicating large machines or dealing with slower WAN links. The following sections detail the results of the test runs, as well as an analysis of the data to help IT administrators understand the performance implications of each parameter on AppAssure Replication. Bandwidth effects AppAssure Replication is affected by the speed of the link between the two replication cores. When replicating within the same data center or between buildings, the available bandwidth may be equal to the full speed of the SAN. In other cases a slower WAN link may be utilized. Figure 2 shows the effect that network link speed can have on the time it takes to complete replication. 9

17 Mbps Time to Replicate (seconds) AppAssure utilizes in-line deduplication and compression and WAN optimized replication. Inline deduplication and compression means that AppAssure processes incoming blocks of data in memory, reducing duplicate blocks and compressing them prior to reaching the AppAssure repository. The resulting data that is stored in repository are the minimal amount of blocks necessary to reconstruct a server back to its last snapshot. WAN optimized replication means that these deduplicated and compressed blocks are sent over the WAN consuming only a fraction of the bandwidth a traditional backup would consume. Thus greatly reducing the time, bandwidth and cost associated with replicating backups to secondary site. Additionally, the small size of the replicated blocks also means replication occurs more frequently (every five minutes) than traditional backups Effects of varying bandwidth speeds Gb 155 Mbps - OC3 45 Mbps - T Figure 2: AppAssure throughput performance and time to replicate data over varying bandwidth speeds. The results in Figure 2 can be summarized as: AppAssure takes full advantage the bandwidth given to it going at rates of 900mbps on a 1Gb link AppAssure supports bonding of the Core s NICs as well as 10Gb NIC s to provide even faster replication speeds In only 5 minutes AppAssure can replicate 40GB of WAN optimized traffic Latency effects For the purpose of this discussion latency is how long it takes a packet of data to travel from one point to another across the network. Latency is inherent in any network. Several factors affect latency in a storage system, including the time it takes to retrieve data off a hard disk, cache hit ratios, and the speed of the connection to a host system. In these tests, the goal was to understand how the latency caused by a WAN link might affect AppAssure Replication. Distance between the two sites will add latency. This means that the round trip (send and acknowledgement) for a data packet exchange will take longer as distance separates the devices. In addition to distance, there are other factors that affect a network packet s round-trip time. For example, the amount and type of network switching and routing devices it encounters 10

18 Mbps along the way will all contribute incrementally to the overall link latency. In many cases the device latencies will add more to overall link latency than distance alone. In the lab test environment, a WAN emulator was used to inject various amounts of latency into the replication network links. We then replicated a volume across the link and measured the time it took to complete the replication. For these tests, a SQL Server database virtual machine (~40GB) was used and ensured that the entire volume was overwritten each time (i.e., 100 percent of the data had changed) before creating an outgoing replication task Throughput measured at varying latencies on a 1GB link No delay 5ms 20ms 80ms Figure 3: AppAssure replication throughput measure at varying latencies. Figure 3 shows that AppAssure is able to replicate data in situations below 20ms of latency before experiencing any significant drop off in speed. In situations where latency is 20ms or higher seeding can be used to minimize speed loss due to high latency. RESULTS SUMMARY As seen in figure 3, when network latency is as low as 5ms AppAssure has the ability to replicate at line speeds. When latency is present on a WAN, throughput is reduced due to the default behavior of TCP. TCP throughput is governed by the size of the receive window (RWIN). The RWIN controls the amount of data that can be sent over the WAN before the sender receives an acknowledgement. As the distance between data centers increases, more data is required to be sent across the WAN at any moment to fill the pipe. If the RWIN is too small the sender will only transmit a small amount of data and then wait for an acknowledgement from the receiver. This is the reason that it is difficult to fill a WAN connection that has latency. Typically, performance starts to suffer with as little as 20ms of latency, equivalent to roughly 1600 kilometers. Figure 3 shows that even as more latency is introduced into the environment such as, 20ms and 80ms AppAssure continues to perform exceptionally well. AppAssure s ability to move a 40GB sever over a link with 80ms latency can be attributed to its ability to provide deduplication and compression with its backups. 11

19 BEST PRACTICE AND RECOMMENDATIONS Create a single volume for AppAssure repository for EqualLogic arrays For Compellent create two volumes for AppAssure repository one for metadata on tier-1 storage and the secondary volume on tier-2 storage Ensure that the AppAssure Core is running on Windows Server 2012 When performing replication ensure that the secondary Core has enough storage for the incoming snapshots Only perform Virtual Standby for 10% of the amount of machines your Core can support Always follow the AppAssure sizing guidelines CONCLUSION In today s datacenter, Do more with less is a common directive from business leaders to the IT staff. In order to meet this requirement, IT staff must leverage all tools that exist in the datacenter to enable the business to grow and thrive. Taking advantage of Dell AppAssure replication provides excellent capabilities for moving protected data across local and geographically distributed sites, enhancing business continuity and disaster recovery options. If an outage occurs, the ability to quickly restore and provide access to business critical data simply and efficiently is critical to the success of today s 24x7x365 business models. As demonstrated by this tech report, Dell AppAssure is a proven solution to help meet these requirements. 12