Hi ,

I would like to share this issue with the community for knowledge sharing, related to repeated PowerVM/VIOS FCA_ERR4 / FCA_ERR12 errors on unused Fibre Channel ports, along with the findings and resolution steps.

Problem

Unused or intentionally disconnected Fibre Channel ports on FC adapters may continue to be configured by cfgdev/cfgmgr, resulting in continuous error log generation.

Symptoms

The following errors may be found in errpt:

LABEL: FCA_ERR12
IDENTIFIER: 29FA8C20

LABEL: FCA_ERR4
IDENTIFIER: 7BFEEA1F

Cause

When unused FC adapter ports remain configured and set to autoconfigure, the system continuously attempts to initialize them, even though they are not physically connected or intended for use.

This behavior generates unnecessary Fibre Channel protocol driver errors and fills the error report logs.

Objective

Prevent:

• FCA_ERR12: 29FA8C20
• FCA_ERR4: 7BFEEA1F

Environment

• AIX
• VIOS
• AIX 7.2 TL5 with 32 GB/s FC NVMe adapters

Resolving the Problem

Step 1 - Disable the unused FC port (VIOS / padmin)

Remove the fcs# device and all child devices:

rmdev -dev fcs# -recursive -ucfg

Set the fscsi# device to not autoconfigure:

chdev -dev fscsi# -attr autoconfig=defined

Step 2 - Re-enable if required in the future

chdev -dev fscsi# -attr autoconfig=available
cfgdev

Step 3 - Root user alternative

Put the adapter in defined state:

rmdev -l fscsiX -R

Disable FC protocol driver:

chdev -l fscsiX -a autoconfig=defined

Enable FC protocol driver:

chdev -l fscsiX -a autoconfig=available

Step 4 - SMIT alternative

Disable:

smitty devices
 → FC adapter
 → FC SCSI I/O Controller Protocol Device
 → Disable a FC SCSI Protocol Device

Enable:

smitty devices
 → FC adapter
 → FC SCSI I/O Controller Protocol Device
 → Enable a FC SCSI Protocol Device

Step 5 - Special procedure for AIX 7.2 TL5 with 32 GB FC NVMe adapters

rmdev -Rl fcnvmeX
chdev -l fcnvmeX -a autoconfig=defined

Verification

Check the autoconfig attribute:

lsattr -El fscsi#

Expected values:

• autoconfig available
• autoconfig defined

Benefits

Disabling intentionally unused FC ports helps:

• Eliminate repetitive FCA_ERR4/FCA_ERR12 errors
• Reduce unnecessary errpt noise
• Improve system monitoring clarity
• Simplify PowerVM/VIOS administration
• Improve operational housekeeping

Important Note

⚠️ These steps are intended only for ports that are intentionally unused and disconnected.

If the affected FC ports should be connected or operational, proper troubleshooting should be performed instead of disabling them.

Additional Information

For larger environments, scripting may also be used to disable multiple intentionally unused adapters while ensuring active production adapters are not mistakenly unconfigured.

IBM Technote Reference

For full details and the official IBM troubleshooting guide, please refer to:

PowerVM/VIOS FCA_ERR4/FCA_ERR12 errors on unused fibrechannel ports
IBM Support Technote

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Anas AlSaleh
IBM Power Systems Software Specialist
Saudi Business Machines ( SBM )
Riyadh
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