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[Launchpad Bug Tracker <1697580@xxxxxxxxxxxxxxxxxx>]

[Expired for OpenStack Compute (nova) because there has been no activity
for 60 days.]

** Changed in: nova
       Status: Incomplete => Expired

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https://bugs.launchpad.net/bugs/1697580

Title:
  Cinder volumes not always attached to instance in order presented

Status in OpenStack Compute (nova):
  Expired

Bug description:
  Description
  ===========

  Our application require a number of Cinder volumes to be attached to
  the Nova instance.  They always need to be attached in the same order,
  the order matter to the software defined storage application.  How
  they are presented in our application determines what "disk" the
  Cinder volume becomes in the application (our software defined storage
  VM has boot, root, coredump, data disks, etc.)

  We use the OpenStack API to create the resources (Cinder, Neutron,
  Nova, etc.) and attach them with a Nova server create call.

  Most of the time the volumes are attached in the correct order, but
  about 1 out of 10 times, the order of the volumes as they are
  presented in the nova API call (Python list) is not preserved.  This
  causes our SDS VM to fail booting because it does not get the disks it
  expects in the correct order.

  Most VMs do not care about the order in which the cinder volumes are
  presented in the VM, in our case it is significant.

  Steps to reproduce
  ==================

  This has been done using the OpenStack API, which is the best way to
  programmatically reproduce the problem, but could likely be done with
  OS CLI as well.

  1. Create a number of Cinder volumes in a way which they can be uniquely identified in the VM instance (different sizes, etc.
  2. Attach volumes to Nova instance and boot.
  3. repeat steps 1 & 2 enough times, and the cinder volumes will be attached to the nova instance in a different order than what was specified.  This can be verified by checking the libvirt XML file that is generated by nova (virsh dumpxml <domain name>).

  
  Expected result
  ===============

  Given an ordered list of Cinder volumes to be attached to a nova
  instance, the expected result is that they are attached in the
  specified order every time.

  Actual result
  =============

  Most times the expected result is true, about 1 out of 10 times, the
  order the volumes are attached to the nova instance is not what is
  expected.

  Environment
  ===========

  RedHat RDO - Liberty

  openstack-nova-compute-12.0.4-1.el7.noarch

  1. Exact version of OpenStack you are running. See the following
    list for all releases: http://docs.openstack.org/releases/

  2. Which hypervisor did you use?

     Libvirt + KVM

  libvirt-daemon-2.0.0-10.el7_3.5.x86_64
  libvirt-daemon-2.0.0-10.el7_3.5.x86_64

  qemu-kvm-common-rhev-2.6.0-28.el7_3.9.x86_64
  qemu-kvm-rhev-2.6.0-28.el7_3.9.x86_64
  libvirt-daemon-driver-qemu-2.0.0-10.el7_3.5.x86_64

  2. Which storage type did you use?

  Cinder NFS driver for Netapp FAS; Cinder iSCSI driver for SolidFire

  3. Which networking type did you use?

  Neutron with openvswitch.

  Logs & Configs
  ==============

  N/A

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