Unable to create customized multipath device

Linux and Unix-Like Red Hat
1

Hi,
I am testing on iSCSI + multipath, where i have one iSCSI lun assigned to one server.

mpatha (1IET     00010001) dm-2 IET,VIRTUAL-DISK
size=100M features='0' hwhandler='0' wp=rw
|-+- policy='round-robin 0' prio=1 status=active
| `- 2:0:0:1 sda 8:0    active ready running
`-+- policy='round-robin 0' prio=1 status=enabled
  `- 3:0:0:1 sdb 8:16   active ready running

and multipath.conf as below ...

# cat /etc/multipath.conf
defaults {
        user_friendly_names     yes
        udev_dir                /dev
        polling_interval        10
        path_grouping_policy    failover
        getuid_callout          "/lib/udev/scsi_id --whitelisted --device=/dev/%n"
        failback                immediate
        no_path_retry           fail
    verbosity        3
}
multipaths {
       multipath {
              wwid     1IET_____00010001
              alias     qdisk_lun
    }
}


blacklist {
}

But it's not working , can you please let me know where i am going wrong ?

2

IF you told us WHAT "is not working", we might be in a position to help you.

3 Likes
3

Hey thanks for response ... i need iSCSI lun to show as qdisk_lun in "multipath -ll" command , but it's showing mpatha instead

4

Dear linux.amrit,

I have a few to questions:-

  • What output/errors do you get?
  • What OS version are you using?
  • Can you not join these up with reference to the files in /dev/disk?

We're all here to learn and getting all the relevant information will help us all. Some of this may well depend on the OS version, so please could you paste the output from uname -a in CODE tags into the thread.

Kind regards,
Robin

5
  • What output/errors do you get? Nothing much error i can see...
  • What OS version are you using?
# uname -a
Linux desktopA.home.org 2.6.32-431.el6.x86_64 #1 SMP Fri Nov 22 03:15:09 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
  • Can you not join these up with reference to the files in /dev/disk*? How to do it ?
# ls -ld /dev/dm-5 
brw-rw----. 1 root disk 253, 5 Sep 26 15:21 /dev/dm-5
# ls -ld /dev/mapper/mpatha 
lrwxrwxrwx. 1 root root 7 Sep 26 15:21 /dev/mapper/mpatha -> ../dm-3

Do you want me to mention /dev/dm-5 on multipath.conf ?

6

I am not sure , but I believe I had a similar issue years ago and I think the answer was setting a filter in lvm.conf so that the multipath device alias is found first before all the other names that point to the same device. Don't know if it is related...

7

issue got resolved ... need to change multipath.conf as below ...

# cat /etc/multipath.conf
defaults {
        user_friendly_names     yes
    getuid_callout "/lib/udev/scsi_id --whitelisted --replace-whitespace --device=/dev/%n"
}
multipaths {
       multipath {
        wwid    1IET_00030001
              alias     datalun01
    }
}

blacklist {
}
2 Likes