Comment 5 for bug 985741

Hi David

1)What do mean storage module in the initrd, is it HBA driver module?

2)I have upgrade to 12.04 LTS this morning, don't see same behavior.
   Please see the unbutu_12.04_multipath.txt

3)see multipath configure in attachment

4)As you request, attach test result before and after creation of LVM
   And also reboot host.

Vincent Chen
EMC2 | E-Lab Linux team

-----Original Message-----
From: <email address hidden> [mailto:<email address hidden>] On Behalf Of David Duffey
Sent: Thursday, April 26, 2012 8:47 AM
To: Chen, Vincent
Subject: [Bug 985741] Re: multipath can't show device on which is setup lvm

Hi Vencent,

Here are some things you can try that might help narrow the problem:

* Re-create the init ramdisk, make sure your storage module is in the initrd
   (what modules are in the initrd, vs what modules are loaded after boot and everything
    is working)
* Can you test this on 12.04 LTS (released April 26th) to see if it has the same behaviour?
* Show the output of multipathd -k"show config"
* Give the output of the following commands before creating the lv, after, and after reboot
   * dmsetup ls --tree
   * dmsetup table

I suspect this can be fixed in the initrd.

David

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https://bugs.launchpad.net/bugs/985741

Title:
  multipath can't show device on which is setup lvm

Status in “multipath-tools” package in Ubuntu:
  Confirmed

Bug description:
  root@SGELLIN119:~# lsb_release -rd
  Description: Ubuntu 11.10
  Release: 11.10

  affect package: multipath-tools, lvm2

  If creating logical volume with Multipath on disk primary partition 1, multipath can’t find the
  disks. Syslog show such error when booting system

  kernel: [ 27.604034] device-mapper: table: 252:5: multipath: error getting device
  kernel: [ 27.604115] device-mapper: ioctl: error adding target to table

  I use fdisk to create two partitions on one physical lun.

  Mpath6:
  /dev/mapper/mpath6-part1
  /dev/mapper/mpath6-part2

  Mpath7:
  /dev/mapper/mpath7-part1
  /dev/mapper/mpath7-part2

  create a logical volume on mpath6-part2, mpath7-part2
  Reboot host, there is no exception and error logs. Multipath could
  Find all devices.

  root@SGELLIN119:~# multipath -ll | grep SYMM
  mpath9 (360000970000192602316533030453335) dm-10 EMC,SYMMETRIX
  mpath8 (360000970000192602316533030453334) dm-6 EMC,SYMMETRIX
  mpath7 (360000970000192602316533030453333) dm-7 EMC,SYMMETRIX
  mpath6 (360000970000192602316533030453332) dm-4 EMC,SYMMETRIX
  mpath5 (360000970000192602316533030453331) dm-3 EMC,SYMMETRIX

  root@SGELLIN119:~# lvs -v
      Finding all logical volumes
    LV VG #Seg Attr LSize Maj Min KMaj KMin Origin Snap% Move Copy% Log Convert LV UUID
    mlv my_vg 1 -wi-a- 1020.00m -1 -1 252 22 c3cECW-CJry-OdXI-O9bZ-lXq8-BUYq-obzcvB
    sym_lv2 sym_vg2 2 -wi-a- 200.00m -1 -1 252 20 1t9SZa-QEEm-2u6p-lCqN-aqcd-xOpn-dC1YAu
    sym_lv3 sym_vg3 2 -wi-a- 200.00m -1 -1 252 21 w4H00r-l71s-UURm-C32C-wDuS-fEF2-wlJFI0

  Then I use same way to create a lv on mpath6-part1 and mpath7-part1
  After rebooting host, there are some error logs happen.
  Multipath can’t find mpath6 and mapth7. Of course the logical volums on
  Mpath6 and mpath7 were lost also.

  root@SGELLIN119:~# multipath -ll| grep SYMM
  mpath9 (360000970000192602316533030453335) dm-3 EMC,SYMMETRIX
  mpath8 (360000970000192602316533030453334) dm-2 EMC,SYMMETRIX
  mpath5 (360000970000192602316533030453331) dm-5 EMC,SYMMETRIX

  root@SGELLIN119:~# lvs -v
      Finding all logical volumes
    LV VG #Seg Attr LSize Maj Min KMaj KMin Origin Snap% Move Copy% Log Convert LV UUID
    mlv my_vg 1 -wi-a- 1020.00m -1 -1 252 1 c3cECW-CJry-OdXI-O9bZ-lXq8-BUYq-obzcvB

  the finding is that if creating lvm on disk primary partition 1. Something were changed and it lead multipath
  couldn’t find devices.

  root@SGELLIN119:~# udevadm info --query=all --name=/dev/mapper/mpath6
  P: /devices/virtual/block/dm-8
  N: dm-8
  L: -100
  S: mapper/mpath6
  S: disk/by-id/dm-name-mpath6
  S: disk/by-id/dm-uuid-mpath-360000970000192602316533030453332
  E: UDEV_LOG=3
  E: DEVPATH=/devices/virtual/block/dm-8
  E: MAJOR=252
  E: MINOR=8
  E: DEVNAME=/dev/dm-8
  E: DEVTYPE=disk
  E: SUBSYSTEM=block
  E: DM_NAME=mpath6
  E: DM_UUID=mpath-360000970000192602316533030453332
  E: DM_SUSPENDED=0
  E: DM_UDEV_RULES=1
  E: DEVLINKS=/dev/mapper/mpath6 /dev/disk/by-id/dm-name-mpath6 /dev/disk/by-id/dm-uuid-mpath-360000970000192602316533030453332

  Value "L" is negative compare to normal one

  Here is an temporary recovery way:
  4) Service multipath-tools stop
  5) Dmsetup remove_all
  6) Service multipath-tools start
  However, the issue is consistent after I reboot OS.

  If I remove lv ( still have LVM package in OS) , multipath work
  well.

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