Xgig peers inside SANs
Finisar's Xgig Analyzer 1.5 provides powerful analysis of iSCSI linksFollow @infoworld
With a few mouse clicks, I captured only iSCSI frames sent on port 3260 from an initiator, building that filter from a comprehensive template that covers the most common protocols. For frequently used and complex filters, you can also create custom templates by dragging and dropping entries from the master template.
After you save the trace, you close TraceControl and launch TraceView. You’ll typically use TraceView to analyze a file saved with TraceControl, but it can also analyze data straight from the tap, which is useful to chase errors interactively.
It’s impossible to mention the numerous features of TraceView in the space allotted here. One that captured my attention is a narrow bar chart at the bottom of the screen that provides an immediate view of the trace file, listing peaks such as a surge of similar frames. That chart is very useful for spotting possible problem areas. Clicking on a peak brings the details into the main pane for further analysis.
To isolate a problem, you can define additional filters using the same comprehensive template seen in TraceControl. You can also filter only frames related to the same port. Moreover, TraceView can automatically color-code entries to mark different protocols or frames.
To facilitate the analysis, TraceView opens a separate pane for details such as source, destination, length, and time of each packet, as well as additional and more detailed information, down to the bit content. Those details are a useful complement to the summary frame data listed in the main pane.
I liked TraceView. If I had to spend many hours analyzing traces, TraceView would be one of the first choices for my toolbox. However, if I had to spend many hours analyzing traces, using Expert Viewer instead would probably cut that time to minutes.
Using Expert Viewer is like having a skilled co-worker point out errors in a trace. In fact, in contrast to TraceView, Expert tries to make sense of all frames in the trace, verifying not only that each frame is correctly formatted, but also that their behavior is consistent within the context of the stream.
Expert Viewer did not detect any error during my regular tests, indicating that the dialog between the software initiators on my server and the Overland Storage box was spotless. However, I triggered quite a few false positives working with badly filtered traffic. For best results, Expert Viewer should have access to the full trace.
After using Xgig for a few weeks, mostly positive remarks populate my test log. Setup can be challenging, but the reward is much needed flexibility and flawless operations.
A last minute check with Finisar silenced one of my few criticisms: Support for 4Gbps FC should be available by the time you read this. If your SAN is getting complicated, you should make room in your budget for Finisar’s Xgig Analyzer. It’s not cheap, but it’s an investment that should quickly produce a sizable return.