The FC Check section is used to verify the quality of the Fibre Channel links of your system by measuring the activity of the FC link status counters.
The test will extract counter information twice. The first pass sets a benchmark and the second pass will do a comparison to that benchmark and report excessive increments.
FC counters are used to isolate transient recoverable errors. If counters activity is within limits, the SAN module can be turned on (in Maintenance -> Maintain Hosts).