Re: Local Partitions detected as Multipath Device

Elvir Kuric <ekuric@xxxxxxxxxx> · Tue, 22 Oct 2013 13:08:42 +0200



    On 10/22/2013 12:17 PM, Zama Ques
      wrote:

    
          My local partitions are detected as multipath device 

          
          $multipath -l

mpathb (360014380125d90420000a000003e0000) dm-9 HP,HSV450
size=200G features='1 queue_if_no_path' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=0 status=active
`- 3:0:0:1 sdb 8:16 active undef running
mpatha (3600508b1001c02143bc59c6862d97353) dm-0 HP,LOGICAL VOLUME
size=137G features='1 queue_if_no_path' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=0 status=active
`- 0:0:0:1 sda 8:0  active undef running

          I added the following lines in multipath.conf so that
            local partitions are not considered as multipath device
          blacklist {
   wwid 3600508b1001c02143bc59c6862d97353
}

          Executed the following commands after that .
          #service multipathd reload

# multipath -F
Oct 22 12:10:42 | mpathb: map in use
Oct 22 12:10:42 | mpatha: map in use

          So , tried rebooting the server , but no luck . Any clues
            to resolve the issue will be highly appreciated . 

          
          Thanks
          Zaman

          
    hi,

    
    /me wonders what OS ( and version ) is in use? service
      multipathd relaod ... suggest it is something RHEL based ( not 100
    % sure ) 

    
    Check /etc/multipath/* files ( if rhel 6 )  and see is there
      WWID from above, and also check initramfs ( RHEL 6 ) or initrd
      file  ( RHEL 5 ) from /boot 

    
    do below 

    
    # mkdir /tmp/initrdtest 

    # cp /boot/initramfs-$$$$.img ( or initrd ... ) /tmp/initrdtest

    
    unpack it 

    
    # cd tmp/initrdtest 

    
    # zcat initrd.img | cpio -i 

    
    and check what is there for multiapth devices written.

    
    In short, I think you will need to ensure there are not records
      for devices you want to blacklist in /etc/multipath/* ( rhel 6 )
      or /var/lib/multipath/*   ( rhel 5 ) and rebuild initramfs /
      initrd ( depending is it RHEL 5 - initrd / RHEL 6 -initramfs  )
      once these records are not present.Rebuilding initrd/initramfs
      will pick values from /etc/multipath/*  ( rhel 6 ) or
      /var/lib/multipath/ ( rhel 5 ) 

      
      to rebuild initrd/initramfs check docs out there  but in short
      process is ( after you remove records for WWID from wwid and
      bindings files - read above ) 

      
      RHEL 5: 

      
      # cd /boot

      # cp initrd-$(uname -r).img initrd-$(uname -r).img.backup [ make
      backup ] 

      # mkinitrd -v -f initrd-$(uname -r).img 

      # reboot ( to boot to new initramfs ) 

      
      RHEL 6: 

      
      same as above with small corrections ;) 

      
    # cd /boot

        # cp initramfs-$(uname -r).img initramfs-$(uname -r).img.backup
        [ make backup ] 

        # dracut -v -f initramfs-$(uname -r).img 

        # reboot ( to boot to new initramfs ) 

        
     good reading https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/DM_Multipath/config_file_blacklist.html
            

        hope this helps 

        
        Kind regards, 

      
    -- 
Elvir Kuric, Senior Technical Support Engineer / Red Hat / GSS EMEA / 
  

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