Volume Manager is unable the see virtual Linux devices if multipathd is managing the paths.

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Article ID: 100025256

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Updated On:

Cause

Customer is using Linux device-mapper to manage the LUN paths not Veritas VxDMP. Their storage administrator created /etc/multipathd.conf file with the definitions of all the paths to the LUNs.
The operating system presents all the paths to LUNs in the "fdisk -ul" output and customer expected to see the paths in 'vxdisk' outputs, too not only the physical LUNs.

Resolution

Ask customer to either remove Linux device-mapper from managing the paths and use Veritas VxDMP only, or as per the below mentioned article ( 000040609 ), should customer need to manage devices with Device Mapper Multipath, one needs to exclude those devices from VxVM access.

Also requested customer to run 'vxdisk path' command to confirm.


# vxdisk path
SUBPATH                     DANAME               DMNAME       GROUP        STATE
sda                         sda                  -            -            ENABLED
sdf                         sdb                  -            -            ENABLED
sdb                         sdb                  -            -            ENABLED
sdi                         sdc                  -            -            ENABLED
sdc                         sdc                  -            -            ENABLED
sdj                         sdd                  -            -            ENABLED
sdd                         sdd                  -            -            ENABLED
sdk                         sde                  -            -            ENABLED
sde                         sde                  -            -            ENABLED
sdl                         sdg                  -            -            ENABLED
sdg                         sdg                  -            -            ENABLED
sdm                         sdh                  -            -            ENABLED
sdh                         sdh                  -            -            ENABLED
sdn                         sdn                  -            -            ENABLED

# vxdisk list sdh
Device:    sdh
devicetag: sdh
type:      auto
info:      format=none
flags:     online ready private autoconfig invalid
pubpaths:  block=/dev/vx/dmp/sdh char=/dev/vx/rdmp/sdh
guid:      -
udid:      HITACHI%5FDF600F%5F85041223%5F000C
site:      -
Multipathing information:
numpaths:   2
sdm     state=enabled
sdh     state=enabled  

 

or just to compare the size of the devices in the 'fdisk -ul' output.

 

$ fdisk -ul |grep dev
Disk /dev/sda: 583.9 GB, 583998111744 bytes
/dev/sda1   *          63      208844      104391   83  Linux
/dev/sda2          208845  1140614999   570203077+  83  Linux
Disk /dev/sdb: 858.9 GB, 858993459200 bytes       <------------------- LUN to use with VxVM
Disk /dev/sdc: 322.1 GB, 322122547200 bytes
Disk /dev/sdd: 322.1 GB, 322122547200 bytes
Disk /dev/sde: 322.1 GB, 322122547200 bytes
Disk /dev/sdf: 858.9 GB, 858993459200 bytes        <------------------- path to the LUN

 

Disk /dev/sdg: 322.1 GB, 322122547200 bytes
Disk /dev/sdh: 322.1 GB, 322122547200 bytes
Disk /dev/sdi: 322.1 GB, 322122547200 bytes
Disk /dev/sdj: 322.1 GB, 322122547200 bytes
Disk /dev/sdk: 322.1 GB, 322122547200 bytes
Disk /dev/sdl: 322.1 GB, 322122547200 bytes
Disk /dev/sdm: 322.1 GB, 322122547200 bytes
Disk /dev/sdn: 220.1 GB, 220117073920 bytes
Disk /dev/dm-0: 858.9 GB, 858993459200 bytes        <------------------- device-mapper path to the LUN

 

Disk /dev/dm-1: 322.1 GB, 322122547200 bytes
Disk /dev/dm-2: 322.1 GB, 322122547200 bytes
Disk /dev/dm-3: 322.1 GB, 322122547200 bytes
Disk /dev/dm-4: 322.1 GB, 322122547200 bytes
Disk /dev/dm-5: 322.1 GB, 322122547200 bytes
Disk /dev/dm-6: 220.1 GB, 220117073920 bytes

Applies To

RHEL 5.3 with device-mapper-multipath-0.4.7-23.el5.src.rpm
Storage Foundation version 5.0 Maintenance Pack 3 and Rolling Patch 3

Issue/Introduction

Customer complained that Volume Manager is unable to pick up new LUNs created by their storage administrator. They can see all their LUNs in 'fdisk -ul' output, but not the /dev/dm-* devices in the 'vxdisk list' one. $ fdisk -ul |grep dev
Disk /dev/sda: 583.9 GB, 583998111744 bytes
/dev/sda1   *          63      208844      104391   83  Linux
/dev/sda2          208845  1140614999   570203077+  83  Linux
Disk /dev/sdb: 858.9 GB, 858993459200 bytes
Disk /dev/sdc: 322.1 GB, 322122547200 bytes
Disk /dev/sdd: 322.1 GB, 322122547200 bytes
Disk /dev/sde: 322.1 GB, 322122547200 bytes
Disk /dev/sdf: 858.9 GB, 858993459200 bytes
Disk /dev/sdg: 322.1 GB, 322122547200 bytes
Disk /dev/sdh: 322.1 GB, 322122547200 bytes
Disk /dev/sdi: 322.1 GB, 322122547200 bytes
Disk /dev/sdj: 322.1 GB, 322122547200 bytes
Disk /dev/sdk: 322.1 GB, 322122547200 bytes
Disk /dev/sdl: 322.1 GB, 322122547200 bytes
Disk /dev/sdm: 322.1 GB, 322122547200 bytes
Disk /dev/sdn: 220.1 GB, 220117073920 bytes
Disk /dev/dm-0: 858.9 GB, 858993459200 bytes
Disk /dev/dm-1: 322.1 GB, 322122547200 bytes
Disk /dev/dm-2: 322.1 GB, 322122547200 bytes
Disk /dev/dm-3: 322.1 GB, 322122547200 bytes
Disk /dev/dm-4: 322.1 GB, 322122547200 bytes
Disk /dev/dm-5: 322.1 GB, 322122547200 bytes
Disk /dev/dm-6: 220.1 GB, 220117073920 bytes       # vxdisk list
DEVICE       TYPE            DISK         GROUP        STATUS
sda          auto:none       -            -            online invalid
sdb          auto:none       -            -            online invalid
sdc          auto:none       -            -            online invalid
sdd          auto:none       -            -            online invalid
sde          auto:none       -            -            online invalid
sdg          auto:none       -            -            online invalid
sdh          auto:none       -            -            online invalid
sdn          auto:none       -            -            online invalid
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