Enable and disable AIX MPIO Multipathing for array devices using vxmpio utility

  • Article ID:100007182
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    To use Dynamic Multipathing (DMP) with AIX disk devices, the AIX native multipathing driver (MPIO) must be disabled for those devices so DMP can then claim and control the paths to the device. This is usually accomplished by installing a software package from the specific array vendor that will remove MPIO definitions from the AIX ODM. Some devices do not have vendor supplied Non-MPIO ODM definitions to disable MPIO. This utility is for removing the MPIO definitions for those devices.


      The vxmpio utility controls whether the specified type of storage array is controlled by MPIO or is claimed under the Veritas Dynamic Multi-Pathing driver. Use the vxmpio utility to disable or enable MPIO for devices with the specified product ID (pid). You must reboot the system for the changes to take effect. When you disable MPIO, the specified devices are claimed under the Veritas Dynamic Multi-Pathing driver after the reboot. When you enable MPIO, the specified devices are removed from Veritas Dynamic Multi-Pathing control and claimed under MPIO.














Error Message

Unable to place disk device under DMP control due to already claimed by MPIO. No vendor supplied non-ODM definitions available.


 Please refer man page of vxmpio,



 Use the vxmpio utility.

Available in Volume Manager 5.0MP3RP5HF6 ( 2511672  - need a generic way to disable MPIO for any array without requiring vendor specific ODM predefines )

Also available in 5.1SP1 and later versions of Volume Manager.


This is an example of how to disable MPIO control of disks on a storage using "vxdmpio".
For this example we will be modifying control of "hdisk9" which resides on SAN-VC.

a) Check the available disks with "vxdisk -e list"

# vxdisk -e list
DEVICE       TYPE           DISK         GROUP        STATUS        OS_NATIVE_NAME   ATTR
disk_0       auto           -             -            LVM          hdisk0           -                                                         
disk_1       auto           -             -            LVM          hdisk1           - 
san_vc0_9    auto:cdsdisk   -             -            online       hdisk9           -


b) Verify a disk is under MPIO control at the Operating System level.
 # lscfg -vl hdisk9
hdisk9 U9179.MHD.06B94ER-V86-C5-T1-W500507680140C156-L0 MPIO IBM 2145 FC Disk

Machine Type and Model......2145
ROS Level and ID............30303030
Serial Number...............2145
Device Specific.(Z0)........0000063268181002
Device Specific.(Z1)........
Device Specific.(Z2)........
Device Specific.(Z3)........

** Note: "MPIO" is included in the description above.
To turn off MPIO for disks on the SAN-VC, it is necessary to identify the disks by the PID of the storage array.
In this case, SAN-VC storage has the identifier "2145".

c) Turn off MPIO control of disks on the SAN (reboot may be required)

 # /etc/vx/bin/vxmpio disable pid='2145'
Running bosboot ..
trustchk: Verification of attributes failed: /usr/sbin/mknod: mode

bosboot: Boot image is 61468 512 byte blocks.
VxVM vxmpio INFO V-5-2-5828 Please reboot the machine to disable MPIO support for 2145

# shutdown -Fr now

d) Verify after reboot, MPIO is now disabled for this storage.
After the reboot, the command for the disk at OS level should no longer show MPIO in the description output.

 # lscfg -vl hdisk9
hdisk9 U9179.MHD.06B94ER-V86-C5-T1-W500507680140C156-L0 IBM 2145 FC Disk


Applies To



OS_LEVEL : AIX 5.3 TL7 or later / AIX 6.1 / AIX 7.1

Product Version :  5.0MP3RP5HF6 or later  and 5.1SP1 or later.




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