Comment 10 for bug 985741

Yes, Peter, you are right.
After I update initramfs, this issue is resolved.
Thanks for your strong support.

Vincent Chen
EMC2 | E-Lab Linux team

-----Original Message-----
From: <email address hidden> [mailto:<email address hidden>] On Behalf Of Peter Petrakis
Sent: Friday, April 27, 2012 9:54 PM
To: Chen, Vincent
Subject: [Bug 985741] Re: multipath can't show device on which is setup lvm

I don't think you need to upgrade at all, your multipathd is sufficiently modern
and not much different from the version in 12.04.

Interesting, I see that you're using user_friendly_names, though since you're also
using LVM, it kind of makes that feature redundant as the LVM is now your
user friendly name, and having that multipath feature adds another level of
 complexity when UDEV is creating devices. Please set "user_friendly_names no" in
 /etc/multipath.conf, and update your initrd "update-initramfs -k all -u". The last
part is important as the multipath.conf is copied to the initrd and used as the
basis for any blacklists or additional UDEV juggling.

What might have happened is you didn't update the initrd since you created the
initial multipath config. Since the default is no, the ramdisk creates the normal
long style WWID names, then it mounts root, multipathd starts which finds user
friendly names set and then begins destroying the original WWID names in
exchange for the mpathx versions. If LVM has claimed the MP device by then,
destruction of the original name (and dmtable entry) will be blocked by reference
counting.

In general, it's imperative that you update the initramfs whenever lvm.conf or
multipath.conf is changed, especially when you're using them together.

https://help.ubuntu.com/12.04/serverguide/multipath-devices.html
#multipath-devices-in-logical-volumes

Also, please adjust your local character encoding to a western font. Some of your text files
look like gibberish e.g.

https://launchpadlibrarian.net/103100334/test_before_after_lvm_reboot.txt
    a¡±¡±a¡±€ (8:144)
mpath9 (252:7)
 a¡±?a¡±€ (65:80)
 a¡±¡±a¡±€ (8:160)
mpath15 (252:12)
 a¡±?a¡±€ (8:224)
 a¡±¡±a¡±€ (8:48)
mpath5-part1 (252:10)
 a¡±¡±a¡±€mpath5 (252:2)
    a¡±?a¡±€ (65:16)
    a¡±¡±a¡±€ (8:96)
mpath14-part1 (252:9)

Thank you. -- Peter

** Changed in: multipath-tools (Ubuntu)
       Status: Confirmed => Incomplete

** Changed in: multipath-tools (Ubuntu)
     Assignee: (unassigned) => Peter Petrakis (peter-petrakis)

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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:
  Incomplete

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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