[Bug 1671397] Re: A VNX LUN will still be recognized as LUNZ after provisioning

[ChristianEhrhardt]

​Thanks KC,
that makes it interesting.

On a restart it stops the service and starts it again - so there is nothing
the running program could take over other than what is in config files.
Yet on a reboot just the same happens, the difference is that the kernel
might have lost some context on the reboot.

While I still can't reproduce in my SAN env which doesn't have a concept
like the LUNZ->VRAID transition I wonder if we could somehow force your
environment to pick up the new data other than rebooting.

rescan-scsi-bus.sh has various options which might help here, please try
them one by one (ordered by increased potential impact to your system)
--forcerescan (rescan existing devs)
--issue-lip (login reset, not sure if that works on your devs or might
reset your provisioning)
--forceremove (drop and re-add each device)

rescan-scsi-bus.sh should call that (also one of the devices changed for
you), but to make sure this is not taking any path through
rescan-scsi-bus.sh that ends without issuing this you could also run as
root:
$ echo 1 > /sys/block/device_name/device/rescan

Please let me know if any of above four options would get your device
properly detected.

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Title:
  A VNX LUN will still be recognized as LUNZ after provisioning

Status in multipath-tools package in Ubuntu:
  New

Bug description:
  1. Attach a Ubuntu 16.04 server to a VNX array through either FC, or iSCSI;
  2. LUNZ will be automatically created as below:
  # sudo ./inq.LinuxAMD64
  Inquiry utility, Version V8.1.1.0 (Edit Level: 2102) built with SYMAPI Version V8.1.1.0 (Edit Level 2102)
  Copyright (c) [1997-2015] EMC Corporation. All Rights Reserved.
  For help type inq -h.

  .......

  -------------------------------------------------------------------
  DEVICE   :VEND    :PROD            :REV   :SER NUM          :CAP(kb)
  -------------------------------------------------------------------
  /dev/sda :Lenovo  :720i            :4.23  :           :   292421632
  /dev/sdb :Lenovo  :720i            :4.23  :           :   292421632
  /dev/sdc :Lenovo  :720i            :4.23  :           :   292421632
  /dev/sdd :Lenovo  :720i            :4.23  :           :   292421632
  /dev/sde :Single  :Flash Reader    :1.00  :           :    31166976
  /dev/sdf :DGC     :LUNZ            :0533  :00000000   :      FAILED
  /dev/sdg :DGC     :LUNZ            :0533  :00000000   :      FAILED

  3. Provision 2 x LUNs from VNX to the Ubuntu 16.04 server, then rescan SCSI bus to reflect the changes. The 2 x LUNs will be recognized as below:
  # sudo ./inq.LinuxAMD64
  Inquiry utility, Version V8.1.1.0 (Edit Level: 2102) built with SYMAPI Version V8.1.1.0 (Edit Level 2102)
  Copyright (c) [1997-2015] EMC Corporation. All Rights Reserved.
  For help type inq -h.

  ..........

  --------------------------------------------------------------------
  DEVICE    :VEND    :PROD            :REV   :SER NUM          :CAP(kb)
  --------------------------------------------------------------------
  /dev/sda  :Lenovo  :720i            :4.23  :           :   292421632
  /dev/sdb  :Lenovo  :720i            :4.23  :           :   292421632
  /dev/sdc  :Lenovo  :720i            :4.23  :           :   292421632
  /dev/sdd  :Lenovo  :720i            :4.23  :           :   292421632
  /dev/sde  :Single  :Flash Reader    :1.00  :           :    31166976
  /dev/sdf  :DGC     :VRAID           :0533  :BB589458   :    18874368
  /dev/sdg  :DGC     :VRAID           :0533  :BB589458   :    18874368
  /dev/sdh  :DGC     :VRAID           :0533  :CA589477   :    29360128
  /dev/sdi  :DGC     :VRAID           :0533  :CA589477   :    29360128
  /dev/dm-0 :DGC     :VRAID           :0533  :CA589477   :    29360128

  4. Based on the output, it can be clearly seen that only one multipath
  device(dm-0) is created. Since we provisioned 2 x LUNs, 2 x multipath
  devices should be created. The one not managed by multipath-tools is
  the LUN with SN BB589458, which re-uses the same native device names
  as the LUNZ devices(in step 2).

  5. Command "multipath -v 3 -ll" will tell the root cause that native
  devices(sdf and sdg) are still recognized as LUNZ devices:

  # sudo multipath -v 3 -ll
  ......
  Mar 09 04:48:42 | sdf: udev property SCSI_IDENT_LUN_VENDOR whitelisted
  Mar 09 04:48:42 | sdf: not found in pathvec
  Mar 09 04:48:42 | sdf: mask = 0x25
  Mar 09 04:48:42 | sdf: dev_t = 8:80
  Mar 09 04:48:42 | sdf: size = 0
  Mar 09 04:48:42 | sdf: vendor = DGC
  Mar 09 04:48:42 | sdf: product = LUNZ
  Mar 09 04:48:42 | sdf: rev = 0533
  Mar 09 04:48:42 | sdf: h:b:t:l = 33:0:0:0
  Mar 09 04:48:42 | sdf: tgt_node_name = iqn.1992-04.com.emc:cx.apm00153919964.a5
  Mar 09 04:48:42 | (null): (DGC:LUNZ) vendor/product blacklisted
  ......
  Mar 09 04:48:42 | sdg: udev property SCSI_IDENT_LUN_VENDOR whitelisted
  Mar 09 04:48:42 | sdg: not found in pathvec
  Mar 09 04:48:42 | sdg: mask = 0x25
  Mar 09 04:48:42 | sdg: dev_t = 8:96
  Mar 09 04:48:42 | sdg: size = 0
  Mar 09 04:48:42 | sdg: vendor = DGC
  Mar 09 04:48:42 | sdg: product = LUNZ
  Mar 09 04:48:42 | sdg: rev = 0533
  Mar 09 04:48:42 | sdg: h:b:t:l = 35:0:0:0
  Mar 09 04:48:42 | sdg: tgt_node_name = iqn.1992-04.com.emc:cx.apm00153919964.b5
  Mar 09 04:48:42 | (null): (DGC:LUNZ) vendor/product blacklisted
  ......

  6. After provisioning LUNs, LUNZ should be removed, and multipath-
  tools should reflected the changes.

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