If you work with NPIV, you might have experienced it: everything is working fine, but there are mysterious errors 7870C5A4 on VIOSes. Disturbing.

vios3b:/root# errpt | grep vfchost
7870C5A4   0620125012 T S vfchost12      Virtual FC Host Adapter detected an erro
7870C5A4   0620125012 T S vfchost12      Virtual FC Host Adapter detected an erro
7870C5A4   0620125012 T S vfchost0       Virtual FC Host Adapter detected an erro
7870C5A4   0620125012 T S vfchost0       Virtual FC Host Adapter detected an erro

vios3b:/root# errpt -a -j 7870C5A4 | more
---------------------------------------------------------------------------
LABEL:          VFC_HOST
IDENTIFIER:     7870C5A4

Date/Time:       Wed Jun 20 12:50:56 GMT+02:00 2012
Sequence Number: 251423
Machine Id:      00F71FD94C00
Node Id:         vios3b
Class:           S
Type:            TEMP
WPAR:            Global
Resource Name:   vfchost12

Description
Virtual FC Host Adapter detected an error

Probable Causes
Virtual FC Host Adapter Driver is an Undefined State

Failure Causes
Virtual FC Host Adapter Driver is an Undefined State

        Recommended Actions
        Remove Virtual FC Host Adapter Instance, then Configure the same instance

Detail Data
ADDITIONAL INFORMATION
        module: npiv_port_sciolst 1.61.1.11     rc: 000000000000004F    location: 00002800
        data:  1 9 29 0 210008
---------------------------------------------------------------------------

The important parts are highlighted in red. Error entries occur every time you run cfgmgr on a client. What's happening? This error shows up, when you have zones between a client NPIV adapter and a number of storage FC ports, but the host mapping on the storage doesn't use all of them. A picture worth of dozens of sentences:

AIX box represents an LPAR with virtual fibre channels. To have the picture easy to read, VIOS and physical connection is not shown in the picture. Blue lines show zoning, orange lines show mapping. There are two zones:

• zone A: fcs0,hba0,hba1,hba2
• zone B: fcs1,hba3,hba4,hba5

And on the storage there are two host mappings (hostconnects on DS8k) defined

• host mapping #1: fcs0,hba0,hba1
• host mapping #2: fcs1,hba4,hba5

There are two storage ports hba2, and hba3 that are part of zone sets, but they are not used to present volumes to the client LPAR. For every port zoned but not mapped, one error entry will be generated in VIOS, while running cfgmgr on the client LPAR. One error 7870C5A4 entry will be generated for the storage port hba2, one will be generated for the storage port hba3.

If you want to get rid of the entries in the error log, align your zoning with the mapping on the storage. Either narrow your zoning, or widen your mapping on the storage. Hope this helps.
BTW: I don't know, what the error means, whether it is a bug, or an ignorable error entry. I just like an empty error log.

Tags:  cfgmgr vios npiv 7870c5a4 error