[Bug 1711749] Comment bridged from LTC Bugzilla

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------- Comment From rosattig at br.ibm.com 2017-09-25 14:49 EDT-------
Hi, I'll try to give a better explanation about what's happening:

1. Problem: After create multiple namespaces for a NVMe device, they are
being detected as mpath disks, which is not correct. The comment above
showed this behavior.

2. Solution: there are 2 upstream commits that solve this issue. (As
shown in the Bug Description)

The nvme devices are being blacklisted by default in multipath. You can
check that by: multipathd -k'show config' | grep nvme -B3

So, in order to reproduce the issue, one must insert the following in
/etc/multipath.conf:

blacklist_exceptions {
devnode "^nvme"
}

After applied those two patches, the issue was fixed:

Running 'multipath -v3 | grep uid_attribute'. (Now it uses ID_WWN
instead of ID_SERIAL for NVMe devices)

Sep 25 08:23:09 | nvme0n1: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n10: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n11: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n12: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n13: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n14: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n15: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n16: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n17: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n18: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n19: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n2: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n20: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n21: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n22: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n23: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n24: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n25: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n26: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n27: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n28: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n29: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n3: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n30: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n31: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n32: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n4: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n5: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n6: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n7: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n8: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme0n9: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | sdb: uid_attribute = ID_SERIAL (config file default)
Sep 25 08:23:09 | sdc: uid_attribute = ID_SERIAL (config file default)
Sep 25 08:23:09 | sdd: uid_attribute = ID_SERIAL (config file default)
Sep 25 08:23:09 | sde: uid_attribute = ID_SERIAL (config file default)
Sep 25 08:23:09 | sdf: uid_attribute = ID_SERIAL (config file default)
Sep 25 08:23:09 | sdg: uid_attribute = ID_SERIAL (config file default)
Sep 25 08:23:09 | sda: uid_attribute = ID_SERIAL (config file default)
Sep 25 08:23:09 | sdh: uid_attribute = ID_SERIAL (config file default)
Sep 25 08:23:09 | nvme1n1: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme2n1: uid_attribute = ID_WWN (controller setting)
Sep 25 08:23:09 | nvme3n1: uid_attribute = ID_WWN (controller setting)

And if I run 'multipath -ll' it shows nothing, since this machine does
not have any other multipath disk.

The patches will be attached next as well as the .debs of the multipath-
tools package after built. So, you guys can review and test it.

If there's anything else missing, please let us know.

Thanks,
Rodrigo

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to multipath-tools in Ubuntu.
https://bugs.launchpad.net/bugs/1711749

Title:
  multipath-tools: Backport 2 patches to Ubuntu 17.10 (NVMe disks are
  detected as multipath disks)

Status in The Ubuntu-power-systems project:
  Incomplete
Status in multipath-tools package in Ubuntu:
  Incomplete

Bug description:
  == Comment: #0 - Rodrigo R. Rosatti Galvao <rosattig at br.ibm.com> - 2017-08-16 12:51:37 ==
  NVMe disks are being detected as multipath disks, as pointed in the BZ 157373. https://bugzilla.linux.ibm.com/show_bug.cgi?id=157373

  There are two upstream commits in multipath-tools that solve this
  issue:

  4dd25783e139 Fill NVMe specific path info
  c2db19ced1ec libmultipath: fix over-long NVME WWIDs 

  In order to solve this issue on Ubuntu, the 2 patches must be
  backported to multipath-tools package.

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