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redhat DM MPIO

Arthur Wang
Arthur Wang asked
on
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Last Modified: 2012-05-07
After following the instruction for dm mpio configuration document:

1: configure the file:

[# Blacklist all devices by default. Remove this to enable multipathing
# on the default devices.
#blacklist {
#        devnode "*"
#}

## By default, devices with vendor = "IBM" and product = "S/390.*" are
## blacklisted. To enable mulitpathing on these devies, uncomment the
## following lines.
#blacklist_exceptions {
#       device {
#               vendor  "IBM"
#               product "S/390.*"
#       }
#}

## Use user friendly names, instead of using WWIDs as names.
defaults {
        user_friendly_names yes
        path_grouping_policy    multibus
}


2: restart the multipath dameon

service multipathd restart

3: list all the path which there are two path
[root@appserver82 /]# multipath -ll
mpath2 (3600c0ff000d7e5625a67994a01000000) dm-2 HP,MSA2312fc
[size=172G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=2][active]
 \_ 0:0:0:2 sda 8:0   [active][ready]
 \_ 0:0:1:2 sdb 8:16  [active][ready]

4: check the disk:

[root@appserver82 /]# fdisk -l

Disk /dev/cciss/c0d0: 73.3 GB, 73372631040 bytes
255 heads, 63 sectors/track, 8920 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

           Device Boot      Start         End      Blocks   Id  System
/dev/cciss/c0d0p1   *           1          13      104391   83  Linux
/dev/cciss/c0d0p2              14        8920    71545477+  8e  Linux LVM

Disk /dev/sda: 184.9 GB, 184999985152 bytes
255 heads, 63 sectors/track, 22491 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sda doesn't contain a valid partition table

Disk /dev/sdb: 184.9 GB, 184999985152 bytes
255 heads, 63 sectors/track, 22491 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn't contain a valid partition table

Disk /dev/dm-2: 184.9 GB, 184999985152 bytes
255 heads, 63 sectors/track, 22491 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/dm-2 doesn't contain a valid partition table
[root@appserver82 /]#

why there are still multiple disks show up? i am supposed to see only one LUN from the SAN.
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