Benefits of deploying Dell SonicWALL WAN Acceleration with Dell EqualLogic storage

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1 Benefits of deploying Dell SonicWALL WAN Acceleration with Dell EqualLogic storage Faster, more efficient data replication and backup between office locations Introduction Data backup and replication processes between an enterprise organization s data center and remote replication sites can be significantly slowed in a wide area network (WAN). The effectiveness of WAN applications including backup and recovery applications often suffers due to overburdened bandwidth. If bandwidth is low, the resulting latency and packet loss over a WAN connection will adversely affect an enterprise s ability to quickly and efficiently achieve recovery time objective (RTO) and recovery point objective (RPO) goals. Backup and replication operations over the WAN may be delayed and disrupted due to slow data replication and long queuing times that result from WAN bandwidth limitations. To get faster data replication and backup between remote sites and LAN-like application performance over the WAN, more organizations are increasingly using Dell EqualLogic PS Series iscsi storage area networks (SANs) along with Dell SonicWALL WAN Acceleration Appliance (WXA) solutions. Background The WXA Series has a proven ability to reduce replication time for storage such as those from Dell EqualLogic. Vendor Model Software revision Dell Dell ( ) V5.2.2 Dell Dell SonicWALL WXA Dell Dell SonicWALL NSA 2400 Firewall 5.8.1

2 Deployment example In this typical network topology example, the WAN could be a site-tosite VPN or an MPLS (multiprotocol label switching) network. The physical network will have inherent latency introduced because of the physical distance between the data center and branch office. For WAN acceleration to provide an appreciable difference in replication time, the round trip latency should be in excess of 40 ms. At the data center core is a Dell SonicWALL Network Security Appliance (NSA) 2400 Next-Generation Firewall. Connected to the firewall via an Ethernet cable over port X2 is a Dell SonicWALL WXA Similarly, the branch office has a Dell SonicWALL TZ 215 firewall, also connected to a WXA WAN Dell appliances are connected to their respective firewalls using a LAN port. This connection may be through a switched or routed network. It is likely that the SAN will have multiple connecting branch offices. The WAN acceleration appliances support multiple branch offices terminating in multiple locations. Data center Branch X2 X2 WXA 2000 NSA 2400 TZ 215 WXA 2000 Figure 1: Deployment example 2

3 Test methodology Dell EqualLogic replication times were measured both with and without a WXA. A WAN emulator was used between sites that allowed varying WAN characteristics, such as bandwidth and latency, to be tested. A site-to-site VPN was configured between the NSA 2400s. Testing methodology: To provide a baseline, performance was initially measured while disabling WAN acceleration on the NSA 2400s. The WAN emulator simulated speeds of E1 (2 Mbps), 4 Mbps, 8 Mbps and 16 Mbps networks. For each of the test cases, one of the bandwidth values listed above was configured on the WAN emulator to replicate the bandwidth of a WAN or SAN connection between Dell EqualLogic replication partners. Before each replication, I/O to the source volume was performed to simulate changed data. In some cases, 100% of the data was changed, while in others only approximately 20% of the volume was modified. The data volume used for the testing was a 300 MB set comprised of a mix of both compressible (Microsoft Office files Word, PowerPoint, Excel, etc.) and hard-to-compress data (.zip and.pdf) designed to reflect a mix typically found in enterprise environments. WAN emulator WXA 2000 NSA 2400 NSA 2400 WXA 2000 Windows 7 Windows Server 2008 R2 Figure 2: Test network overview 3

4 Test results and analysis 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 Dell EqualLogic Auto-Replication, both with and without a Dell SonicWALL WAN Acceleration solution. Bandwidth effects To establish a baseline, we replicated a 300 MB volume from the branch office to the data center across the simulated WAN link, and measured the time it took without the Dell SonicWALL WXA. WAN acceleration was then enabled on the firewall. In these tests, a replication was performed first with no changes and then again with a 20% change rate to show the effects of history-based de-duplication. The graph above shows the replication performance with traffic history-based de-duplication. By applying a 20% change to the volume, the WXA provided, on average, a 75% reduction in replication time and more than a 75% reduction in data volume. Replication time varying bandwidths EqualLogic and WXA 2nd pass EqualLogic and WXA 20% change 16 Mbps Equalogic without WXA Bandwidth 2 Mbps ,000 1,200 1,400 1,800 Seconds Figure 3: Replication time varying bandwidths 4

5 Latency effects In another test, we varied the latency on a single bandwidth rate of 8 Mbps. Figure 4 demonstrates that varying the latency also has a significant effect on data transfer times. This is due to the chatty nature of WAN transport protocols and the back-and-forth messaging required when transferring data across the WAN, such as acknowledgments of receipt of data and confirmation of ready-to-receive data status. As shown, the higher the latency, the greater the improvement in replication time achieved with WAN acceleration. Replication times with varying latency 500 ms Latency 250 ms EqualLogic and WXA 2nd pass EqualLogic and WXA 20% change Equalogic without WXA 125 ms 0 1,000 2,000 3,000 4,000 5,000 Seconds Figure 4: Replication times with varying latency A round-trip packet latency of 125 ms is expected across large continents. A round-trip latency of 250 ms is expected on transatlantic or intercontinental traffic, while a round-trip latency of 500 ms is typical for satellite-based WAN connections. Replication of a volume with a 20% change that would normally take 37 minutes on a transatlantic link can now be completed in seven minutes. 5

6 Conclusion Dell SonicWALL WXA works in conjunction with Dell EqualLogic PS Series replication to implement efficient data compression and de-duplication over WAN connections. In doing so, the Dell SonicWALL WXA significantly reduces replication-based WAN traffic and enables more efficient replications. Using Dell EqualLogic storage with a Dell SonicWALL WXA provides the following benefits: Reduces replication times by up to 90% Reduces required bandwidth by up to 90% Enables more efficient business-day replications Provides integrated management with Dell SonicWALL Next-Generation Firewalls Deployment options include hardware appliances or virtual appliances Runs on standard Dell server hardware Together, Dell EqualLogic PS Series SANs and Dell SonicWALL WXAs enable organizations to deploy higher performance, secure data protection, thus safeguarding critical business data. 05/13 DS 0402L