Volume cannot be created in VNX Storage Pool with disks missing

[Jeegn Chen]

When limited disks are missing and Storage Pool is not Offline, the VNX LUN created on that Storage Pool won't be in Ready State but the LUN is still OK for IO access.

Current implementation of create_volume in VNX Cinder Driver will wait until the VNX LUN gets into Ready State or timeout.
Thus the new volume in the back end corresponding to the pool will stuck at "creating" state for a long time before the disks are replaced. This reduces the high availability of the back end.

The logic should be adjusted so that the new volume can get into "available" state as long as the corresponding VNX LUN can serve IO.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/167573

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/167573
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=b1537c016e74afb403a75158710c4242fd5a31a6
Submitter: Jenkins
Branch: master

commit b1537c016e74afb403a75158710c4242fd5a31a6
Author: peter_wang <email address hidden>
Date: Wed Mar 25 02:35:32 2015 -0400

    Enhance VNX Cinder volume creation logic

    Sometimes sysadmin needs to remove broken disks and replace them
    with some new disks. Before the disks are replaced and fully rebuilt,
    the pool would be in "Faulted" state, and all LUNs created in this
    pool would be in "Faulted" state as well.
    A LUN in this "Faulted" state is still OK for IO access.

    Current implementation of create_volume in VNX Cinder Driver will
    wait until the VNX LUN gets into Ready State or timeout.
    Thus the new volume in the back end corresponding to the pool will
    be stuck at creating state for a long time before disks are replaced.
    This reduces the high availability of the back end.

    The change allows new volume to get into available state as long as
    the corresponding VNX LUN can serve IO.

    Change-Id: Ifb152b3b9c59ce0d5c875129a7bf0503740d5a3a
    Closes-Bug: 1436241