Troubleshooting and Fine-Tuning
If your data protection deployment is not meeting performance targets after configuring the SteelHeads using the methods described in this chapter, examine the following system components for potential bottlenecks:
Application Servers - Are the server and client fast enough? To perform a LAN baseline check, put the SteelHeads in bypass mode and connect the servers directly through a high-bandwidth network with zero latency to see how fast they are. Time permitting, you might want to do this LAN baselining before introducing the SteelHeads into the test environment. LAN-Side Network - Make sure that there are no issues with the LAN-side network between the SteelHeads and any data protection hosts. In particular, on the LAN, there should be no packet loss, and the round trip latency between the SteelHeads and hosts should be less than one millisecond for the fastest possible throughput. Interface errors, especially those related to Ethernet duplex negotiation, are a leading factors of LAN-side network issues. WAN-Side Network - Use MX-TCP to overcome any WAN-side packet loss caused by deficient links or undersized router interface queues. If the WAN bandwidth is being fully utilized during optimized data transfers, then the WAN is the bottleneck. If the WAN link is not fully utilized, options like RiOS SDR-A or SDR-M can increase the LAN-side throughput.CPU - Check the CPU reports to see if the CPU cores are the bottleneck. If some cores are busy but some are not, enable multicore load balancing. If you enable multicore load balancing and all cores are fully utilized, you might require a larger model SteelHead. Disk - You can use disk-related metrics to determine that the disk is the bottleneck for higher levels of throughput. Always assess these metrics relative to empirical application performance. Even if they indicate heavy disk utilization, it does not necessarily mean that the disk is the bottleneck. In cases where the disk is the bottleneck, then you can adjust the adaptive data streamlining settings progressively upward to either SDR-A, SDR-M or, finally, compression-only. In some cases, you might need to upgrade to a higher model SteelHead. Consult with your Riverbed Sales or Professional Services representative. Data Store Disk Load - If the RiOS Data Store Read Efficiency report, accessible from the Management Console, shows that read efficiency falls below 50% consistently, this might indicate that the disk is the bottleneck.