IOM3 Fault message on DS4243

[AlexeyF]

Hello

We have an error on our old out of support disk array on the disk shelf DS4243

storage show fault
Enclosure Status: non-critical
Channel: 0a
Shelf: 3
Shelf Type: DS4243

.............

SAS Connectors:
Element Status Status Bytes Status Descriptions
1 [IOM3 A] : OK 01,03,FF,00
2 [IOM3 A] : OK 01,03,FF,00
3 [IOM3 B] : OK 01,03,FF,00
4 [IOM3 B] : OK 01,03,FF,00

Vendor Unique Element 83-IOM3:
Element Status Status Bytes Status Descriptions
1 [IOM3 A] : NONCRITICAL 03,04,00,00 BACKPLANE VPD FAULT
2 [IOM3 B] : OK 01,08,00,00 MASTER

Vendor Unique Element 85-IOM3:
Element Status Status Bytes Status Descriptions
1 [IOM3 A] : OK 01,60,00,00
2 [IOM3 B] : OK 01,60,00,00

I would like to understand how critical is this issue (I see it's written noncritical :)) ). 

Does this mean that one of the two SAS IO modules on the disk shelf is not functioning so all the disks are being accessed via one path only?

Or is it only one of four paths (2 paths in every SAS module?) that is down?

[Ontapforrum · Accepted solution]

Does this mean that one of the two SAS IO modules on the disk shelf is not functioning so all the disks are being accessed via one path only?
No.

Or is it only one of four paths (2 paths in every SAS module?) that is down?
No.

Shelf architecture has two EEPROMs containing Vital Product Data (VPD). Upon boot, the I/O Module (IOM) attempts to read and verify the contents of both EEPROMs. Having redundant VPDs allows the system to continue operating when these issues are encountered. However, the reported error should be addressed at the soonest opportunity.

As the system is out of support, Try VPD troubleshooting steps..

https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Systems/FAS_Systems/VPD_midplane_compare_test_fails_with_%22midplane_compare_test_failur...

https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Systems/FAS_Systems/Disk_shelf_reports_the_critical_warning__non-critical_status%3B_Back...