Switches Overview
Purpose: The SAN fabric between hosts and arrays. Fibre channel error trending, port licensing and utilization, and the alert queue. It is the section that explains latency neither the host nor the array can account for.
Why the fabric gets missed
When storage is slow, the host reports high latency and the array reports healthy service times, and both are telling the truth. The delay is in between. SAN switches are rarely monitored with the same discipline as the equipment either side of them, which makes fabric errors a common cause of problems that appear to have no cause.
The reports in this section
| Report | What it answers |
|---|---|
| Enterprise SAN Switch Summary | Whether fabric errors are rising, and how many ports are used, free, or unlicensed |
| Switch Health Alerts | Which specific switches and ports are erroring, with acknowledgment and escalation |
A third slot exists in the Switches navigation that is not yet documented here. Its page will be added when source material is available.
Common actions
Read the summary for direction, then the alerts for location. An error count that is rising sharply is worth investigating before anything else in this section, because fibre channel errors cause retransmission, and retransmission is indistinguishable from slow storage at the application layer.
Tips
Switch device names and port targets identify fabric endpoints and commonly encode site codes. Redact them before sharing screenshots from this section.
Related screens
Enterprise Host Summary carries a connected-switch count per host, which is the fabric redundancy check. Host LUNs shows the per-LUN latency a fabric problem produces.