Netapp: Image cloning unsuccessful, "need more than 2 values to unpack"

[Christoph Dwertmann]

I just upgraded to the kilo 2015.1.1 packages, and Netapp Flex cloning from glance stopped working.

# dpkg -l | grep cinder
ii cinder-api 1:2015.1.1-0ubuntu2~cloud2 all Cinder storage service - API server
ii cinder-backup 1:2015.1.1-0ubuntu2~cloud2 all Cinder storage service - Scheduler server
ii cinder-common 1:2015.1.1-0ubuntu2~cloud2 all Cinder storage service - common files
ii cinder-scheduler 1:2015.1.1-0ubuntu2~cloud2 all Cinder storage service - Scheduler server
ii cinder-volume 1:2015.1.1-0ubuntu2~cloud2 all Cinder storage service - Volume server
ii python-cinder 1:2015.1.1-0ubuntu2~cloud2 all Cinder Python libraries
ii python-cinderclient 1:1.1.1-0ubuntu1~cloud0 all python bindings to the OpenStack Volume API

cinder-volume log:

2015-09-01 16:20:12.852 27743 INFO cinder.volume.drivers.netapp.dataontap.nfs_base [req-ef38d425-a61f-477d-8abd-b2727dbd45e2 50d450c6c59a4201aa6baf2af7943455 a27858aecba74f5e8aeac7977207c273 - - -] Checking image clone a5aa3603-c014-420e-8799-31c7ff853838 from glance share.
2015-09-01 16:20:12.853 27743 DEBUG cinder.volume.drivers.netapp.dataontap.nfs_base [req-ef38d425-a61f-477d-8abd-b2727dbd45e2 50d450c6c59a4201aa6baf2af7943455 a27858aecba74f5e8aeac7977207c273 - - -] Found possible share matches [u'10.1.0.9:/vol/vault_tier1'] _check_share_in_use /usr/lib/python2.7/dist-packages/cinder/volume/drivers/netapp/dataontap/nfs_base.py:579
2015-09-01 16:20:12.861 27743 DEBUG cinder.volume.drivers.netapp.dataontap.nfs_7mode [req-ef38d425-a61f-477d-8abd-b2727dbd45e2 50d450c6c59a4201aa6baf2af7943455 a27858aecba74f5e8aeac7977207c273 - - -] Share match found for ip 10.1.0.9 _share_match_for_ip /usr/lib/python2.7/dist-packages/cinder/volume/drivers/netapp/dataontap/nfs_7mode.py:199
2015-09-01 16:20:12.866 27743 INFO cinder.volume.drivers.netapp.dataontap.nfs_base [req-ef38d425-a61f-477d-8abd-b2727dbd45e2 50d450c6c59a4201aa6baf2af7943455 a27858aecba74f5e8aeac7977207c273 - - -] Image cloning unsuccessful for image a5aa3603-c014-420e-8799-31c7ff853838. Message: need more than 2 values to unpack

The problem seems to be that _get_capacity_info() in drivers/netapp/dataontap/nfs_base.py returns a tuple, whereas in drivers/nfs.py three values are expected:

        total_size, total_available, total_allocated = \
            self._get_capacity_info(nfs_share)

[Christoph Dwertmann (cdwertmann)]

Looks like the issue was introduced in https://github.com/openstack/cinder/commit/5ff9497e906c0d41a6b6ef59f057073eeb0fa1c6

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/223385

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/223385
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=cc651ff8c658c4f8d4415d46a348136b653ab30a
Submitter: Jenkins
Branch: master

commit cc651ff8c658c4f8d4415d46a348136b653ab30a
Author: Tom Barron <email address hidden>
Date: Thu Sep 10 19:53:29 2015 -0400

    Fix NetApp clone from glance failure

    When glance and cinder are backed by the same NetApp DOT flexvol
    container, exposed as an NFS share, a direct clone is attempted
    of the backing files rather than a copy. With the advent of
    kilo 2015.1.1, this clone operation fails with the message:
    "Image cloning unsuccessful ... need more than 2 values to unpack."

    The issue here is that the clone path code is calling the parent
    nfs class _is_share_eligible() method to see if there is enough
    space on the destination flexvol and this method calls _get_capacity_info()
    expecting a three-tuple to be returned. However, commit
    e52f304313efc695f7dd89c222041bffd53c131a deliberately changed the return
    values of _get_capacity_info() within the NetApp drivers to return
    a 2-tuple, based on API calls to obtain capacity information from
    the NetApp storage arrays. That commit missed that this method
    would also be invoked by the parent nfs class _is_share_eligible()
    method, which expects a different signature.

    The fix in this commit is to replace the call to the parent
    _is_share_eligible() method with a more appropriate NetApp class
    specific _share_has_space_for_clone() method. This new method
    uses the NetApp version of _get_capacity_info to get space information
    from the arrays via NetApp apis and expects a 2-tuple to be returned
    from this method.

    Change-Id: Ib0c69e5ea7b32d17930fe0bdcdb9357fd4e4a244
    Closes-bug: 1490845

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/kilo
Review: https://review.openstack.org/225185

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/225185
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=e9dfe5a45971000f458ddcdfee426e3c1ada3a1d
Submitter: Jenkins
Branch: stable/kilo

commit e9dfe5a45971000f458ddcdfee426e3c1ada3a1d
Author: Tom Barron <email address hidden>
Date: Thu Sep 10 19:53:29 2015 -0400

    Fix NetApp clone from glance failure

    When glance and cinder are backed by the same NetApp DOT flexvol
    container, exposed as an NFS share, a direct clone is attempted
    of the backing files rather than a copy. With the advent of
    kilo 2015.1.1, this clone operation fails with the message:
    "Image cloning unsuccessful ... need more than 2 values to unpack."

    The issue here is that the clone path code is calling the parent
    nfs class _is_share_eligible() method to see if there is enough
    space on the destination flexvol and this method calls _get_capacity_info()
    expecting a three-tuple to be returned. However, commit
    e52f304313efc695f7dd89c222041bffd53c131a deliberately changed the return
    values of _get_capacity_info() within the NetApp drivers to return
    a 2-tuple, based on API calls to obtain capacity information from
    the NetApp storage arrays. That commit missed that this method
    would also be invoked by the parent nfs class _is_share_eligible()
    method, which expects a different signature.

    The fix in this commit is to replace the call to the parent
    _is_share_eligible() method with a more appropriate NetApp class
    specific _share_has_space_for_clone() method. This new method
    uses the NetApp version of _get_capacity_info to get space information
    from the arrays via NetApp apis and expects a 2-tuple to be returned
    from this method.

    Note that although this is a cherry-pick, changes were made
    because NetApp Kilo drivers do not support scheduler-based
    over-subscription, only the legacy driver-based NFS over-subscription
    options.

        Conflicts:
            cinder/tests/test_netapp_nfs.py
            cinder/tests/unit/volume/drivers/netapp/dataontap/test_nfs_base.py
            cinder/tests/unit/volume/drivers/netapp/dataontap/test_nfs_cmode.py

    Change-Id: Ib0c69e5ea7b32d17930fe0bdcdb9357fd4e4a244
    Closes-bug: 1490845
    (cherry picked from commit cc651ff8c658c4f8d4415d46a348136b653ab30a)