Help with Multipath

Linux and Unix-Like Red Hat
1

Hi All,

When I execute "multipath -ll" command that time display only 3 path (orafra2,oradata2 and oradata1), not display other 2 path (orafra1 and data1). I have configure 5 path in "/etc/multipath.conf" file. What is the reason behind it. Please help me.

Please find below some output for help:

[root@reuxeuls003 ~]# multipath -ll
orafra2 (360060160a71e2100de29aae7f4f9de11) dm-10 DGC,RAID 10
size=200G features='1 queue_if_no_path' hwhandler='1 emc' wp=rw
|-+- policy='round-robin 0' prio=1 status=active
| |- 1:0:1:3 sds        65:32 active ready  running
| `- 0:0:1:3 sdi        8:128 active ready  running
`-+- policy='round-robin 0' prio=0 status=enabled
  |- 1:0:0:3 sdn        8:208 active ready  running
  `- 0:0:0:3 sdd        8:48  active ready  running
oradata2 (360060160951e2100ccc3b4800798df11) dm-9 DGC,RAID 10
size=200G features='1 queue_if_no_path' hwhandler='1 emc' wp=rw
|-+- policy='round-robin 0' prio=1 status=active
| |- 1:0:0:4 sdo        8:224 active ready  running
| `- 0:0:0:4 sde        8:64  active ready  running
`-+- policy='round-robin 0' prio=0 status=enabled
  |- 1:0:1:4 sdt        65:48 active ready  running
  `- 0:0:1:4 sdj        8:144 active ready  running
oradata1 (360060160a71e210002263e3fbde0dd11) dm-11 DGC,RAID 10
size=300G features='1 queue_if_no_path' hwhandler='1 emc' wp=rw
|-+- policy='round-robin 0' prio=1 status=active
| |- 1:0:0:0 sdk        8:160 active ready  running
| `- 0:0:0:0 sda        8:0   active ready  running
`-+- policy='round-robin 0' prio=0 status=enabled
  |- 1:0:1:0 sdp        8:240 active ready  running
  `- 0:0:1:0 sdf        8:80  active ready  running

Output of "multipath.conf" file:

[root@reuxeuls003 ~]# egrep -v "^#|^$" /etc/multipath.conf
defaults {
        user_friendly_names yes
}
multipaths {
        multipath {
                wwid                    360060160a71e210002263e3fbde0dd11
                alias                   oradata1
        }
        multipath {
                wwid                    360060160951e2100ccc3b4800798df11
                alias                   oradata2
        }
        multipath {
                wwid                    360060160a71e21009a4a0a180fe7dd11
                alias                   orafra1
        }
        multipath {
                wwid                    360060160a71e210080492a4f0fe7dd11
                alias                   data1
        }
        multipath {
                wwid                    360060160a71e2100de29aae7f4f9de11
                alias                   orafra2
        }
}
[root@reuxeuls003 ~]#

Output of "/var/log/messages" :

[root@reuxeuls003 ~]# tail -10f /var/log/messages
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: table: 253:13: multipath: error getting device
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: ioctl: error adding target to table
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: multipath emc: long trespass command will be send
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: multipath emc: honor reservation bit will not be set (default)
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: table: 253:13: multipath: error getting device
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: ioctl: error adding target to table
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: multipath emc: long trespass command will be send
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: multipath emc: honor reservation bit will not be set (default)
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: table: 253:13: multipath: error getting device
Aug 10 07:49:11 reuxeuls003 kernel: device-mapper: ioctl: error adding target to table

Please find the attached output of "multipath -v3"

Please help me.
Thanks in advance.

2

Have you rescaned SCSI/FC bus for host to see the new luns ?

These commands should work :

echo 1 > /sys/class/fc_host/host0/issue_lip
echo 1 > /sys/class/fc_host/host1/issue_lip
echo "- - -" > /sys/class/scsi_host/host0/scan
echo  "- - -" > /sys/class/scsi_host/host1/scan

There can be also some vendor specific scripts/tools, like HP's fibre utils, so check if you have those before issuing above commands.

After re-scan restart multipath deamon and checki if /dev/mapper/orafra1 and /dev/mapper/data1 are created which you use further in your disk configuration (for creating volume groups, logical volumes etc.)

Hope that helps
Regards
Peasant.

3

If possible, You can try rebooting the switch & rescan the disks; followed by restarting the multipath deamon (or alternatively, the server itself.)

4

We can't restart the server. Because this is production server :o.
We are already restart multipath.

5

Paths are added initatially 3 then its increased to 5 ? if yes need scsi-rescan or else reboot. Either is not done it wont reflect your stroage changes at OS end.