Skip to main content
NetApp Knowledge Base

How to verify Linux fibre channel configurations with multipathing I/O (MPIO)

Views:
1,966
Visibility:
Public
Votes:
1
Category:
data-ontap-8
Specialty:
SAN
Last Updated:

Applies to

  • SAN
  • Data ONTAP 8 7-Mode
  • FlexPod
  • Data ONTAP 7 and Earlier

Description

Syslog and EMS messages

[hostname: scsitarget.partnerPath.misconfigured:error]: FCP Partner Path Misconfigured.
[hostname: scsitarget.partnerPath.misconfigured:error]: FCP Partner Path Misconfigured - Host I/O access through a non-primary and non-optimal path was detected.

Please see the article, What do FCP Partner Path Misconfigured messages mean?

Terminology 

  • Partner Path:  Any path to LUNs that utilizes the partner node to access a LUN hosted by the local node.  The LUNs are in an active-active cluster.
  • Non-primary path:  Synonymous with partner path, proxy path and secondary path.  All are examples of a non-primary path.
  • FCP target port:  The fibre channel interface that provides FCP service to hosts.
  • Virtual Target Interconnect (VTIC) - The virtual FCP target interface seen in the initiator group list.  VTIC is used to indicate that the initiator has access to a secondary path.

Problem Description

SANs often provide multiple paths to allow hosts to access LUNs. To maximize the redundancy of the SAN, the host operating system must use multipathing I/O (MPIO) software. MPIO software monitors all available paths and will decide which path should be used for the operating system.  Linux distributions based on the 2.6 series kernel make use of the device mapper plug-in known as dm-multipath. Dm-multipath groups paths of equal priority to allow load balancing of I/O, in addition to path failover. Dm-multipath uses a callout program such as mpath_prio_netapp or mpath_prio_ontap to differentiate primary and secondary paths. The system must perform all I/O to this LUN using device mapper devices (e.g. /dev/mapper/mpath0) in order for dm-multipath to route to the SCSI devices belonging to the primary paths.  The following process outlines how to observe the MPIO configuration. Steps to setup the MPIO configuration are documented in the FCP Linux Host Utilities.

Sign in to view the entire content of this KB article.

New to NetApp?

Learn more about our award-winning Support

NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.