StorCase Technology FC-to-SCSI Single & Dual RAID - Manual (Page 162)

FC-SCSI Dual RAID Module User's Guide - Rev. A01 StorCase Technology, Inc.
Appendix C - Troubleshooting149
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LK LED (FC host port) is lit and the host sees arrays, but performance is very slow.
The probable cause is a bad FC cable. Ensure that the cable is connected properly. Check
the cable for any damage.
NOTE: DO NOT bend the LC (optical) cable beyond the cable's minimum bend radius, data
transmission degradation may occur. Follow cable manufacturer's guidelines for
bend radius limitation.
•
FC host port and switch/HBA do not establish a link.
One possible cause may be that both are set to Auto. Disconnect the FC cable and try changing
the FC host port topology to Loop or Point to Point according to host, and reconnect cable.
Another cause may be that both are set to different speeds. Check to make sure the speeds
are set to the same rate.
•
FC-ALs are configured, but FC devices not found.
Check the Activity LEDs on the controller (refer to Figure 2A & 2B for further information). If
any of these LEDs are not lit, the probable cause is an "open" loop within the FC-AL
configuration. Make sure there are no SFP Modules installed in any open Host ports on the
controller (Auto Loopback is enabled when there are no SFP Modules installed in the open Host
ports). If SFP Modules are installed, make sure that each is connected to an FC device.
For stand-alone configurations, make sure only RAID Controller A Host ports are used to
connect to FC Hosts 0 & 1. RAID Controller B Host ports are for loop expansion only. Auto
Loopback is enabled when there are no SFP Modules installed in the open Host ports.
Array Problems
•
Array is much smaller than it should be.
The backoff percentage may be set higher than 1%, which is causing the array to be much
smaller than the full size of its member disks.
The backoff percentage reduces the capacity of the array by the given percentage. The
backoff percentage helps when assigning spares by compensating for the minor capacity
differences that occur between drive manufacturers. It allows the user to work with drives
of the same nominal capacity, but with dfferent actual capacities (for example, two 18GB
drives from different manufacturers may differ in capacity by 100MB).
The default setting is 1% backoff. Once set, the backoff percentage affects all arrays created
on the controller.