High Impact / Highly Pervasive APAR IJ57855 Some FC adapters may not recover from temporary SAN errors

Description

Certain fibre channel adapters may not recover from SAN errors that would normally cause only temporary link down events.
Affected adapters include any that use the cvfcdd driver. Identify if these adapters are in use by the VIOS or AIX partition by running the following as root:

lsdev -c adapter | grep fcs | grep 7710

or

odmget -q ddins=pci/cvfcdd CuDv

This issue can occur when SFP monitoring or 'fcstat -e' command is executed before a link transition (link up or link down). As a result, environments that regularly run 'fcstat -e' to collect adapter statistics are at higher risk of encountering the problem.

Once triggered, the adapter remains in a link-down state and recovery may require an LPAR reboot.

As a temporary workaround until the corrective fix is applied, avoid running 'fcstat -e' and SFP-monitoring utilities on systems equipped with affected adapters.