mirror of https://github.com/ceph/ceph
69 lines
2.4 KiB
ReStructuredText
69 lines
2.4 KiB
ReStructuredText
==================
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RBD Snapshotting
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==================
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One of the advanced features of RADOS block devices is that you can create
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snapshots of the images to retain a history of an image's state. Ceph supports
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RBD snapshots from the ``rbd`` command, from a kernel object, from a
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KVM, and from cloud solutions. Once you create snapshots of an image, you
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can rollback to a snapshot, list snapshots, remove snapshots and purge
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the snapshots.
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.. important:: To use use RBD snapshots, you must have a running Ceph cluster.
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.. important:: Generally, you should stop i/o before snapshotting an image.
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If the image contains a filesystem, the filesystem should be in a
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consistent state before snapshotting too.
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Create Snapshot
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---------------
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To create a snapshot with ``rbd``, specify the ``snap create`` option,
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the pool name, the image name and the username. If you use ``cephx`` for
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authentication, you must also specify a key or a secret file. ::
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rbd --name {user-name} --keyfile=/path/to/secret --pool {pool-name} snap create --snap {snap-name} {image-name}
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For example::
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rbd --name client.admin --pool rbd snap create --snap foo.snapname foo
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List Snapshots
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--------------
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To list snapshots of an image, specify the pool name, the image name, and
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the username. If you use ``cephx`` for authentication, you must also
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specify a key or a secret file. ::
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rbd --name {user-name} --keyfile=/path/to/secret --pool {pool-name} snap ls {image-name}
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For example::
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rbd --name client.admin --pool rbd snap ls foo
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Rollback Snapshot
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-----------------
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To rollback a snapshot with ``rbd``, specify the ``snap rollback`` option,
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the pool name, the image name and the username. If you use ``cephx`` for
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authentication, you must also specify a key or a secret file. ::
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rbd --name {user-name} --keyfile=/path/to/secret --pool {pool-name} snap rollback --snap {snap-name} {image-name}
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For example::
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rbd --name client.admin --pool rbd snap rollback --snap foo.snapname foo
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Delete a Snapshot
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-----------------
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To delete a snapshot with ``rbd``, specify the ``snap rm`` option,
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the pool name, the image name and the username. If you use ``cephx`` for
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authentication, you must also specify a key or a secret file. ::
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rbd --name {user-name} --keyfile=/path/to/secret --pool {pool-name} snap rm --snap {snap-name} {image-name}
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For example::
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rbd --name client.admin --pool rbd snap rm --snap foo.snapname foo
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