Xgig peers inside SANs
Finisar's Xgig Analyzer 1.5 provides powerful analysis of iSCSI linksFollow @infoworld
Investing in diagnostic tools for networked storage bears several benefits. With the proper tools, you can easily shorten the time it takes to get to the root of performance problems in a complex storage infrastructure. Moreover, even when nothing is broken, a good diagnostic tool can provide a better understanding of your SAN’s inner workings, knowledge that can help you improve the performance and resilience of your storage networks over the long haul.
Late last year Finisar released Xgig Analyzer 1.5, a new version of its popular SAN analysis tool. Xgig 1.5 maintains the capability of previous versions to do flexible and accurate diagnosis on FC (Fibre Channel) networks, and adds similar features for iSCSI and FCIP (Fibre Channel over IP) protocols, extending its support to the quickly growing area of IP-based storage.
Finisar offers different models of Xgig tailored to different analysis requirements. They range from a portable single-blade model to a rack-mountable four-blade version, all sharing the same analysis software. Finisar sent me a desktop unit which I’ve been using in my tests of storage networking equipment. It’s about the size of a shoebox, and includes two blades for analyzing FC and GbE networks, each hosting four 2Gbps FC ports.
Tap and trace
The first step to setting up the Xgig is to invoke the Xgig character-based management application via serial connection and set an IP address. After that you use a Web-based management tool to configure other settings, and to update the Xgig’s software via FTP if necessary.
The Xgig software works in synergy with a suite of applications that includes Expert Viewer, Performance Monitor, TraceControl, and TraceView. Their self-descriptive names give away their functions, but I should clarify that they run on a separate Windows console and interact with the Xgig to capture and analyze traces or monitor performance.
The Xgig architecture gives you great flexibility. You can position a unit to monitor a single device or plug it behind a switch to monitor the traffic from multiple devices. Or you can position a number of Xgig blades at different locations in your SAN and monitor them from the same workstation. Moreover, your applications won’t miss a beat while you monitor or analyze their traffic; the Xgig is completely transparent to the storage network.
For this review, my goal was to analyze the traffic flowing to and from an iSCSI array in my test network, namely the Overland Storage RA2000I reviewed in February. After connecting the Xgig to my SAN then back to the machine hosting Xgig’s software suite, I launched the main application, TraceControl.
TraceControl auto-discovers Xgigs on the LAN and remembers findings in future runs. The first time you use it, you simply type the IP address of the Xgig, press the “discover” button, and TraceControl opens a window showing the Xgig and the ports available on each blade.
TraceControl doesn’t analyze data, but collects information for later analysis with TraceView or Expert Viewer. However, you can program TraceControl to collect only selected data, filtering according to a protocol, to specific frames, or just for errors, which is extremely helpful because it narrows the capture to the specific information you need.
Filters and frames