EMM Module - Loss of Communication

What Caused the Problem?

Communication has been lost to one of the dual EMM modules in a expansion enclosure. The expansion enclosure has only one I/O path available. The Recovery Guru Details area provides specific information you will need as you follow the recovery steps.

Caution: Electrostatic discharge can damage sensitive components. Always use proper antistatic protection when handling components. Touching components without using a proper ground may damage the equipment.

Important Notes

Correct this failure as soon as possible. Although the expansion enclosure is still operational, a level of redundancy has been lost. If the other EMM module or its communication path fails, all I/O to that expansion enclosure will fail.
The Recovery Guru will report separate problems for any expansion enclosures it cannot reach through the particular loop (channel) containing the affected expansion enclosure.
The Recovery Guru Details area will report the affected expansion enclosure and the working channel over which it can communicate with the expansion enclosure.
The fault LED on an EMM module only glows when performing its self-test during power up or has failed the self-test. The fault LED turns off after the self-test is completed successfully.
Both EMM modules in the same expansion enclosure must have the same firmware version and be of the same hardware type.
The EMM modules should contain a label to differentiate between the different hardware types. Make sure that the labels on both EMMs match if you need to replace one of the EMM modules.
Depending on the EMM problem, the RAID controller module may set the associated physical disk channel to a degraded state. This condition is covered in the recovery steps.

Recovery Steps

Fix any other problems reported by the Recovery Guru before attempting to fix this problem.

To determine the non-working channel, start at the physical disk channel on the RAID controller module enclosure corresponding to the working channel (refer to the labels on the back of the RAID controller module enclosure if needed).

Trace the cable from the working channel to the optimal EMM module in the affected expansion enclosure.

Caution: Possible loss of data accessibility. Do not disconnect any cables on the working channel. Disconnecting any cables on the working channel will result in loss of access to your data.

Blink the other EMM module in the affected expansion enclosure (this is the module on the non-working channel).

Reseating the EMM module on the non-working channel may clear the failure being reported.

While the cables are still connected, remove the EMM module from the expansion enclosure.

Note: The Service Action Allowed status in the Details area is always NO for this problem because the component is not failed. In this situation, it is acceptable to remove the battery even though the Service Action Allowed is NO.

Wait 10 seconds, and then re-insert the module firmly.

Wait 40 seconds, and then click the Recheck button to rerun the Recovery Guru to ensure the failure has been fixed.

If	Then
This failure is no longer reported in the Summary area	If a "Degraded Physical Disk Channel" problem is also being reported in the Summary area, then go to step 10; otherwise, you are finished with this procedure.
This failure is still reported in the Summary area	Go to step 6.

If...

Then...

The cable is connected directly to the EMM module on the non-working channel

Remove the cable.

Go to step 7.

The cable is connected to an interface transceiver such as a GBIC or SFP

Leave the cable connected and remove the interface transceiver from the EMM module.

Go to step 7.

Repeat step 5 to check the Service action (removal) allowed status for the EMM, and then replace the EMM module on the non-working channel using the following notes:

Make sure that the replacement EMM module is the same as the EMM that is remaining in the expansion enclosure (hardware type and firmware version).
If the affected expansion enclosure uses EMM modules with external switches, verify that they are set to the same values as the switches on the remaining EMM.
Wait 40 seconds for the storage array to detect and register the EMM module.
Go to step 8.

Reconnect the cable or interface transceiver to the replaced EMM module and wait 40 seconds. If a "Degraded Physical Disk Channel" problem is also being reported in the Summary area, then go to step 9; otherwise, go to step 10.

Select the Advanced >> Troubleshooting >> Physical Disk Channels pull-down menu option, highlight the degraded physical disk channel, and then click the Set Optimal button.

Note: The physical disk channel status may automatically be reset to Degraded if the RAID controller module again determines that the channel is not operating properly.

Click the Recheck button to rerun the Recovery Guru. The failure should no longer appear in the Summary area. If the failure appears again, contact your technical support representative.