Oracle Linux 6.5 multipath misconfiguration

cdthurman — Thu, 05 Jun 2025 05:12:56 GMT

We inherited a Oracle Linux 6.5 server with a multipathing problem. It's connected to a FAS3170 HA pair, 8.1.3P1 7-mode, with 2xQLE2560 HBAs. ALUA is enabled on the igroups, SAN zoning looks correct, but all I/O traverses one HBA and one target port on the NetApp. This is causing a lot of traffic to traverse the vtic and "FCP partner path mismatch" errors.

On the server, we see multipathd errors getting device and ioctl errors "adding target to table." multipath -ll output looks like this:

mpathv (WWID...) dm-29 NETAPP,LUN

size=500G features=`1 queue_if_no_path` hwhandler=`1 alua` wp=rw

|-+- policy='round-robin 0' prio=50 status=active

| |- 7:0:1:13 sdau 66:224 active ready running

| `- 8:0:0:13 sdca 68:224 active ready running

`-+- policy='round-robin 0' prio=10 status=enabled

| 7:0:0:13 sdo 8:224 active ready running

`- 8:0:1:13 sddg 70:224 active ready running

NetApp Linux Host Utility Kit version 6.2 is installed. The sanlun lun show -pv all output for one lun:

ONTAP Path: netapp3:/vol/DataA/data1.lun

LUN: 13

LUN size: 500.1g

Controller CF State: Cluster Enabled

Controller Partner: netapp4

Mode: 7

Multipath Provider: Unknown

-------

state path type /dev/ node host adapter controller target port

up secondary sddg host8 0c

up primary sdca host8 0d

up primary sdau host7 0c

up secondary sdo host7 0d

On this disk, iostat shows all I/O going to /dev/sdo, from adapter host7 to target netapp4:0d across the vtic to netapp3.

I think there's something wrong in the multipath.conf:

defaults {
   user_friendly_names   yes
   max_fds           max
   flush_on_last_del   yes
   queue_without_daemon   no
}

devices {
   device {
       vendor           "NETAPP"
       product           "LUN"
       path_grouping_policy   group_by_prio
       prio           "alua"
       getuid_callout       "/lib/udev/scsi_id -g -u -d /dev/%n"
       path_checker       tur
       path_selector       "round-robin 0"
       hardware_handler   "1 alua"
       failback       immediate
       rr_weight       uniform
       rr_min_io       128
       no_path_retry       queue
   }
}

I notice that user_friendly_names is set to "yes" where best practice is "no." I want to change this, but I don't know if this is the problem.

Are the multipath.conf defaults and device section necessary anymore in after 6.4? The HUK 6.2 Installation and Setup Guide and Recommended Host Settings aren't clear. The Install Guide makes it seem the blacklist is all that's needed. The SnapDrive 5.2.2 documentation is clear on pages 131-132 : You do not have to set any values in the /etc/multipath.conf file if you are using either Red Hat Enterprise Linux (RHEL) 6.4 or later or Oracle Linux 6.4 or later. However, SnapDrive for UNIX configuration you must still maintain a dummy /etc/multipath.conf file, which can either be empty or contain the blacklisting info, if required.

Do these errors look like a multipath.conf problem?

Thank you for reading and any advice would be appreciated.

Clint

Knowledge Base Articles used:

What do FCP Partner Path Misconfigured messages mean?

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

topic Oracle Linux 6.5 multipath misconfiguration in ONTAP Hardware

Oracle Linux 6.5 multipath misconfiguration