d6c1f6a103
At present all virt drivers provide a cleanup method that takes a single destroy_disks boolean to indicate when the underlying storage of an instance should be destroyed. When cleaning up after an evacuation or revert resize the value of destroy_disks is determined by the compute layer calling down both into the check_instance_shared_storage_local method of the local virt driver and remote check_instance_shared_storage method of the virt driver on the host now running the instance. For the Libvirt driver the initial local call will return None when using the shared block RBD imagebackend as it is assumed all instance storage is shared resulting in destroy_disks always being False when cleaning up. This behaviour is wrong as the instance disks are stored separately to the instance directory that still needs to be cleaned up on the host. Additionally this directory could also be shared independently of the disks on a NFS share for example and would need to also be checked before removal. This change introduces a backportable workaround configurable for the Libvirt driver with which operators can ensure that the instance directory is always removed during cleanup when using the RBD imagebackend. When enabling this workaround operators will need to ensure that the instance directories are not shared between computes. Future work will allow for the removal of this workaround by separating the shared storage checks from the compute to virt layers between the actual instance disks and any additional storage required by the specific virt backend. Related-Bug: #1761062 Partial-Bug: #1414895 Change-Id: I8fd6b9f857a1c4919c3365951e2652d2d477df77
25 lines
1.1 KiB
YAML
25 lines
1.1 KiB
YAML
---
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other:
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- |
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The ``[workarounds]/ensure_libvirt_rbd_instance_dir_cleanup`` configuration
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option has been introduced. This can be used by operators to ensure that
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instance directories are always removed during cleanup within the Libvirt
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driver while using ``[libvirt]/images_type = rbd``. This works around known
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issues such as `bug 1414895`_ when cleaning up after an evacuation and
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`bug 1761062`_ when reverting from an instance resize.
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Operators should be aware that this workaround only applies when using the
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libvirt compute driver and rbd images_type as enabled by the following
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configuration options:
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* ``[DEFAULT]/compute_driver = libvirt``
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* ``[libvirt]/images_type = rbd``
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.. warning:: Operators will need to ensure that the instance directory
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itself, specified by ``[DEFAULT]/instances_path``, is not shared between
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computes before enabling this workaround, otherwise files associated with
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running instances may be removed.
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.. _bug 1414895: https://bugs.launchpad.net/nova/+bug/1414895
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.. _bug 1761062: https://bugs.launchpad.net/nova/+bug/1761062
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