Troubleshooting The Fibre Channel Hub; System Reported Error Or Failure To Access A Device; Visually Inspect Leds; Check For Problems On Attached Devices - IBM TotalStorage 300 Service Manual

Troubleshooting the Fibre Channel hub

Attention:
unplug cables or GBICs when there is activity on the associated ports. This will
cause immediate failure of the communications path. To determine if a port has
active communications, see "Visually inspect LEDs" If it becomes necessary to
unplug active ports, the you must stop communications on these ports.
Always begin problem determination by checking the following areas.
v System reported error or failure to access a device
v Visually inspect LEDs
v Determine if zoning is in effect
v Check for problems on attached devices
Before performing any repair action, gather as much information as possible.

System reported error or failure to access a device

Either the customer has reported a IBM NAS 300 related system error message or
the customer has reported a failure accessing IBM NAS 300 storage. If the host
reported error message from the IBM NAS 300 is known, or a customer
communications failure symptom is known, see Table 6 on page 31 After identifying
the error message or the symptom, perform the recommended service action.

Visually inspect LEDs

Observe the front panel LED status indicators, then check the information in Table 6
action.

Check for problems on attached devices

To determine if the source of the problem is an attached device, check the
following:
v
v Display panels
v Firmware levels

Checking the Fibre Channel hub

Attention:
v Blinking green: This is a normally operating port with communications in
v Steady green: The port is connected to a functional device, but there is no data
Use the following procedure to ensure that the Use the following procedure to
ensure that the Fibre Channel hub is good.
1. Remove the incoming cables from the suspect ports. Mark them to make sure
2. Remove and reseat the GBIC in port 7 if it is installed.
30
IBM NAS 300 Service Guide
If you are going to service a functional Fibre Channel hub, never
on page 31. If a faulty condition is observed, perform the recommended service
LEDs
Do not remove cables or GBIC from ports that are:
progress.
traffic in progress. If this port is believed to be the problem, the failure is not with
the Fibre Channel hub. Instead, the attached device or host is not attempting to
send data. See the appropriate host, device, or application documentation to
resolve the problem.
that you can return them to the same port.