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https://github.com/ceph/ceph
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787 lines
29 KiB
ReStructuredText
787 lines
29 KiB
ReStructuredText
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===============================================
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rbd -- manage rados block device (RBD) images
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===============================================
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.. program:: rbd
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Synopsis
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========
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| **rbd** [ -c *ceph.conf* ] [ -m *monaddr* ] [--cluster *cluster-name*]
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[ -p | --pool *pool* ] [ *command* ... ]
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Description
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===========
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**rbd** is a utility for manipulating rados block device (RBD) images,
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used by the Linux rbd driver and the rbd storage driver for QEMU/KVM.
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RBD images are simple block devices that are striped over objects and
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stored in a RADOS object store. The size of the objects the image is
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striped over must be a power of two.
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Options
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=======
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.. option:: -c ceph.conf, --conf ceph.conf
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Use ceph.conf configuration file instead of the default /etc/ceph/ceph.conf to
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determine monitor addresses during startup.
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.. option:: -m monaddress[:port]
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Connect to specified monitor (instead of looking through ceph.conf).
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.. option:: --cluster cluster-name
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Use different cluster name as compared to default cluster name *ceph*.
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.. option:: -p pool-name, --pool pool-name
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Interact with the given pool. Required by most commands.
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.. option:: --no-progress
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Do not output progress information (goes to standard error by
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default for some commands).
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Parameters
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==========
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.. option:: --image-format format-id
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Specifies which object layout to use. The default is 2.
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* format 1 - (deprecated) Use the original format for a new rbd image. This
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format is understood by all versions of librbd and the kernel rbd module,
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but does not support newer features like cloning.
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* format 2 - Use the second rbd format, which is supported by
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librbd and kernel since version 3.11 (except for striping). This adds
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support for cloning and is more easily extensible to allow more
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features in the future.
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.. option:: -s size-in-M/G/T, --size size-in-M/G/T
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Specifies the size of the new rbd image or the new size of the existing rbd
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image in M/G/T. If no suffix is given, unit M is assumed.
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.. option:: --object-size size-in-B/K/M
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Specifies the object size in B/K/M. Object size will be rounded up the
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nearest power of two; if no suffix is given, unit B is assumed. The default
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object size is 4M, smallest is 4K and maximum is 32M.
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.. option:: --stripe-unit size-in-B/K/M
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Specifies the stripe unit size in B/K/M. If no suffix is given, unit B is
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assumed. See striping section (below) for more details.
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.. option:: --stripe-count num
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Specifies the number of objects to stripe over before looping back
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to the first object. See striping section (below) for more details.
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.. option:: --snap snap
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Specifies the snapshot name for the specific operation.
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.. option:: --id username
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Specifies the username (without the ``client.`` prefix) to use with the map command.
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.. option:: --keyring filename
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Specifies a keyring file containing a secret for the specified user
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to use with the map command. If not specified, the default keyring
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locations will be searched.
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.. option:: --keyfile filename
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Specifies a file containing the secret key of ``--id user`` to use with the map command.
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This option is overridden by ``--keyring`` if the latter is also specified.
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.. option:: --shared lock-tag
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Option for `lock add` that allows multiple clients to lock the
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same image if they use the same tag. The tag is an arbitrary
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string. This is useful for situations where an image must
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be open from more than one client at once, like during
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live migration of a virtual machine, or for use underneath
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a clustered filesystem.
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.. option:: --format format
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Specifies output formatting (default: plain, json, xml)
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.. option:: --pretty-format
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Make json or xml formatted output more human-readable.
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.. option:: -o krbd-options, --options krbd-options
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Specifies which options to use when mapping or unmapping an image via the
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rbd kernel driver. krbd-options is a comma-separated list of options
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(similar to mount(8) mount options). See kernel rbd (krbd) options section
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below for more details.
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.. option:: --read-only
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Map the image read-only. Equivalent to -o ro.
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.. option:: --image-feature feature-name
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Specifies which RBD format 2 feature should be enabled when creating
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an image. Multiple features can be enabled by repeating this option
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multiple times. The following features are supported:
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* layering: layering support
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* striping: striping v2 support
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* exclusive-lock: exclusive locking support
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* object-map: object map support (requires exclusive-lock)
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* fast-diff: fast diff calculations (requires object-map)
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* deep-flatten: snapshot flatten support
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* journaling: journaled IO support (requires exclusive-lock)
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* data-pool: erasure coded pool support
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.. option:: --image-shared
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Specifies that the image will be used concurrently by multiple clients.
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This will disable features that are dependent upon exclusive ownership
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of the image.
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.. option:: --whole-object
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Specifies that the diff should be limited to the extents of a full object
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instead of showing intra-object deltas. When the object map feature is
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enabled on an image, limiting the diff to the object extents will
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dramatically improve performance since the differences can be computed
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by examining the in-memory object map instead of querying RADOS for each
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object within the image.
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.. option:: --limit
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Specifies the limit for the number of snapshots permitted.
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Commands
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========
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.. TODO rst "option" directive seems to require --foo style options, parsing breaks on subcommands.. the args show up as bold too
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:command:`bench` --io-type <read | write | readwrite | rw> [--io-size *size-in-B/K/M/G/T*] [--io-threads *num-ios-in-flight*] [--io-total *size-in-B/K/M/G/T*] [--io-pattern seq | rand] [--rw-mix-read *read proportion in readwrite*] *image-spec*
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Generate a series of IOs to the image and measure the IO throughput and
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latency. If no suffix is given, unit B is assumed for both --io-size and
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--io-total. Defaults are: --io-size 4096, --io-threads 16, --io-total 1G,
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--io-pattern seq, --rw-mix-read 50.
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:command:`children` *snap-spec*
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List the clones of the image at the given snapshot. This checks
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every pool, and outputs the resulting poolname/imagename.
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This requires image format 2.
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:command:`clone` [--object-size *size-in-B/K/M*] [--stripe-unit *size-in-B/K/M* --stripe-count *num*] [--image-feature *feature-name*] [--image-shared] *parent-snap-spec* *child-image-spec*
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Will create a clone (copy-on-write child) of the parent snapshot.
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Object size will be identical to that of the parent image unless
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specified. Size will be the same as the parent snapshot. The --stripe-unit
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and --stripe-count arguments are optional, but must be used together.
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The parent snapshot must be protected (see `rbd snap protect`).
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This requires image format 2.
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:command:`cp` (*src-image-spec* | *src-snap-spec*) *dest-image-spec*
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Copy the content of a src-image into the newly created dest-image.
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dest-image will have the same size, object size, and image format as src-image.
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:command:`create` (-s | --size *size-in-M/G/T*) [--image-format *format-id*] [--object-size *size-in-B/K/M*] [--stripe-unit *size-in-B/K/M* --stripe-count *num*] [--thick-provision] [--no-progress] [--image-feature *feature-name*]... [--image-shared] *image-spec*
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Will create a new rbd image. You must also specify the size via --size. The
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--stripe-unit and --stripe-count arguments are optional, but must be used together.
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If the --thick-provision is enabled, it will fully allocate storage for
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the image at creation time. It will take a long time to do.
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Note: thick provisioning requires zeroing the contents of the entire image.
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:command:`deep cp` (*src-image-spec* | *src-snap-spec*) *dest-image-spec*
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Deep copy the content of a src-image into the newly created dest-image.
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Dest-image will have the same size, object size, image format, and snapshots as src-image.
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:command:`device list` [-t | --device-type *device-type*] [--format plain | json | xml] --pretty-format
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Show the rbd images that are mapped via the rbd kernel module
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(default) or other supported device.
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:command:`device map` [-t | --device-type *device-type*] [--read-only] [--exclusive] [-o | --options *device-options*] *image-spec* | *snap-spec*
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Map the specified image to a block device via the rbd kernel module
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(default) or other supported device (*nbd* on Linux or *ggate* on
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FreeBSD).
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The --options argument is a comma separated list of device type
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specific options (opt1,opt2=val,...).
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:command:`device unmap` [-t | --device-type *device-type*] [-o | --options *device-options*] *image-spec* | *snap-spec* | *device-path*
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Unmap the block device that was mapped via the rbd kernel module
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(default) or other supported device.
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The --options argument is a comma separated list of device type
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specific options (opt1,opt2=val,...).
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:command:`diff` [--from-snap *snap-name*] [--whole-object] *image-spec* | *snap-spec*
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Dump a list of byte extents in the image that have changed since the specified start
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snapshot, or since the image was created. Each output line includes the starting offset
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(in bytes), the length of the region (in bytes), and either 'zero' or 'data' to indicate
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whether the region is known to be zeros or may contain other data.
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:command:`du` [-p | --pool *pool-name*] [*image-spec* | *snap-spec*]
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Will calculate the provisioned and actual disk usage of all images and
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associated snapshots within the specified pool. It can also be used against
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individual images and snapshots.
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If the RBD fast-diff feature is not enabled on images, this operation will
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require querying the OSDs for every potential object within the image.
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:command:`export` [--export-format *format (1 or 2)*] (*image-spec* | *snap-spec*) [*dest-path*]
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Export image to dest path (use - for stdout).
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The --export-format accepts '1' or '2' currently. Format 2 allow us to export not only the content
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of image, but also the snapshots and other properties, such as image_order, features.
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:command:`export-diff` [--from-snap *snap-name*] [--whole-object] (*image-spec* | *snap-spec*) *dest-path*
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Export an incremental diff for an image to dest path (use - for stdout). If
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an initial snapshot is specified, only changes since that snapshot are included; otherwise,
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any regions of the image that contain data are included. The end snapshot is specified
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using the standard --snap option or @snap syntax (see below). The image diff format includes
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metadata about image size changes, and the start and end snapshots. It efficiently represents
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discarded or 'zero' regions of the image.
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:command:`feature disable` *image-spec* *feature-name*...
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Disable the specified feature on the specified image. Multiple features can
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be specified.
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:command:`feature enable` *image-spec* *feature-name*...
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Enable the specified feature on the specified image. Multiple features can
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be specified.
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:command:`flatten` *image-spec*
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If image is a clone, copy all shared blocks from the parent snapshot and
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make the child independent of the parent, severing the link between
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parent snap and child. The parent snapshot can be unprotected and
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deleted if it has no further dependent clones.
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This requires image format 2.
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:command:`group create` *group-spec*
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Create a group.
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:command:`group image add` *group-spec* *image-spec*
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Add an image to a group.
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:command:`group image list` *group-spec*
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List images in a group.
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:command:`group image remove` *group-spec* *image-spec*
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Remove an image from a group.
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:command:`group ls` [-p | --pool *pool-name*]
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List rbd groups.
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:command:`group rename` *src-group-spec* *dest-group-spec*
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Rename a group. Note: rename across pools is not supported.
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:command:`group rm` *group-spec*
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Delete a group.
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:command:`group snap create` *group-snap-spec*
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Make a snapshot of a group.
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:command:`group snap list` *group-spec*
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List snapshots of a group.
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:command:`group snap rm` *group-snap-spec*
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Remove a snapshot from a group.
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:command:`group snap rename` *group-snap-spec* *snap-name*
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Rename group's snapshot.
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:command:`image-meta get` *image-spec* *key*
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Get metadata value with the key.
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:command:`image-meta list` *image-spec*
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Show metadata held on the image. The first column is the key
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and the second column is the value.
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:command:`image-meta remove` *image-spec* *key*
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Remove metadata key with the value.
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:command:`image-meta set` *image-spec* *key* *value*
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Set metadata key with the value. They will displayed in `image-meta list`.
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:command:`import` [--export-format *format (1 or 2)*] [--image-format *format-id*] [--object-size *size-in-B/K/M*] [--stripe-unit *size-in-B/K/M* --stripe-count *num*] [--image-feature *feature-name*]... [--image-shared] *src-path* [*image-spec*]
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Create a new image and imports its data from path (use - for
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stdin). The import operation will try to create sparse rbd images
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if possible. For import from stdin, the sparsification unit is
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the data block size of the destination image (object size).
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The --stripe-unit and --stripe-count arguments are optional, but must be
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used together.
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The --export-format accepts '1' or '2' currently. Format 2 allow us to import not only the content
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of image, but also the snapshots and other properties, such as image_order, features.
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:command:`import-diff` *src-path* *image-spec*
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Import an incremental diff of an image and applies it to the current image. If the diff
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was generated relative to a start snapshot, we verify that snapshot already exists before
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continuing. If there was an end snapshot we verify it does not already exist before
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applying the changes, and create the snapshot when we are done.
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:command:`info` *image-spec* | *snap-spec*
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Will dump information (such as size and object size) about a specific rbd image.
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If image is a clone, information about its parent is also displayed.
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If a snapshot is specified, whether it is protected is shown as well.
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:command:`journal client disconnect` *journal-spec*
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Flag image journal client as disconnected.
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:command:`journal export` [--verbose] [--no-error] *src-journal-spec* *path-name*
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Export image journal to path (use - for stdout). It can be make a bakcup
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of the image journal especially before attempting dangerous operations.
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Note that this command may not always work if the journal is badly corrupted.
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:command:`journal import` [--verbose] [--no-error] *path-name* *dest-journal-spec*
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Import image journal from path (use - for stdin).
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:command:`journal info` *journal-spec*
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Show information about image journal.
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:command:`journal inspect` [--verbose] *journal-spec*
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Inspect and report image journal for structural errors.
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:command:`journal reset` *journal-spec*
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Reset image journal.
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:command:`journal status` *journal-spec*
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Show status of image journal.
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:command:`lock add` [--shared *lock-tag*] *image-spec* *lock-id*
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Lock an image. The lock-id is an arbitrary name for the user's
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convenience. By default, this is an exclusive lock, meaning it
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will fail if the image is already locked. The --shared option
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changes this behavior. Note that locking does not affect
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any operation other than adding a lock. It does not
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protect an image from being deleted.
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:command:`lock ls` *image-spec*
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Show locks held on the image. The first column is the locker
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to use with the `lock remove` command.
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:command:`lock rm` *image-spec* *lock-id* *locker*
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Release a lock on an image. The lock id and locker are
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as output by lock ls.
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:command:`ls` [-l | --long] [*pool-name*]
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Will list all rbd images listed in the rbd_directory object. With
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-l, also show snapshots, and use longer-format output including
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size, parent (if clone), format, etc.
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:command:`merge-diff` *first-diff-path* *second-diff-path* *merged-diff-path*
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Merge two continuous incremental diffs of an image into one single diff. The
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first diff's end snapshot must be equal with the second diff's start snapshot.
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The first diff could be - for stdin, and merged diff could be - for stdout, which
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enables multiple diff files to be merged using something like
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'rbd merge-diff first second - | rbd merge-diff - third result'. Note this command
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currently only support the source incremental diff with stripe_count == 1
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:command:`mirror image demote` *image-spec*
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Demote a primary image to non-primary for RBD mirroring.
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:command:`mirror image disable` [--force] *image-spec*
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Disable RBD mirroring for an image. If the mirroring is
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configured in ``image`` mode for the image's pool, then it
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can be explicitly disabled mirroring for each image within
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the pool.
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:command:`mirror image enable` *image-spec*
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Enable RBD mirroring for an image. If the mirroring is
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configured in ``image`` mode for the image's pool, then it
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can be explicitly enabled mirroring for each image within
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the pool.
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This requires the RBD journaling feature is enabled.
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:command:`mirror image promote` [--force] *image-spec*
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Promote a non-primary image to primary for RBD mirroring.
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:command:`mirror image resync` *image-spec*
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Force resync to primary image for RBD mirroring.
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:command:`mirror image status` *image-spec*
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Show RBD mirroring status for an image.
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:command:`mirror pool demote` [*pool-name*]
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Demote all primary images within a pool to non-primary.
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Every mirroring enabled image will demoted in the pool.
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:command:`mirror pool disable` [*pool-name*]
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Disable RBD mirroring by default within a pool. When mirroring
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is disabled on a pool in this way, mirroring will also be
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disabled on any images (within the pool) for which mirroring
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was enabled explicitly.
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:command:`mirror pool enable` [*pool-name*] *mode*
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Enable RBD mirroring by default within a pool.
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The mirroring mode can either be ``pool`` or ``image``.
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If configured in ``pool`` mode, all images in the pool
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with the journaling feature enabled are mirrored.
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If configured in ``image`` mode, mirroring needs to be
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explicitly enabled (by ``mirror image enable`` command)
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on each image.
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:command:`mirror pool info` [*pool-name*]
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Show information about the pool mirroring configuration.
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It includes mirroring mode, peer UUID, remote cluster name,
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and remote client name.
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:command:`mirror pool peer add` [*pool-name*] *remote-cluster-spec*
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Add a mirroring peer to a pool.
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*remote-cluster-spec* is [*remote client name*\ @\ ]\ *remote cluster name*.
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The default for *remote client name* is "client.admin".
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This requires mirroring mode is enabled.
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:command:`mirror pool peer remove` [*pool-name*] *uuid*
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Remove a mirroring peer from a pool. The peer uuid is available
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from ``mirror pool info`` command.
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:command:`mirror pool peer set` [*pool-name*] *uuid* *key* *value*
|
|
Update mirroring peer settings.
|
|
The key can be either ``client`` or ``cluster``, and the value
|
|
is corresponding to remote client name or remote cluster name.
|
|
|
|
:command:`mirror pool promote` [--force] [*pool-name*]
|
|
Promote all non-primary images within a pool to primary.
|
|
Every mirroring enabled image will promoted in the pool.
|
|
|
|
:command:`mirror pool status` [--verbose] [*pool-name*]
|
|
Show status for all mirrored images in the pool.
|
|
With --verbose, also show additionally output status
|
|
details for every mirroring image in the pool.
|
|
|
|
:command:`mv` *src-image-spec* *dest-image-spec*
|
|
Rename an image. Note: rename across pools is not supported.
|
|
|
|
:command:`object-map check` *image-spec* | *snap-spec*
|
|
Verify the object map is correct.
|
|
|
|
:command:`object-map rebuild` *image-spec* | *snap-spec*
|
|
Rebuild an invalid object map for the specified image. An image snapshot can be
|
|
specified to rebuild an invalid object map for a snapshot.
|
|
|
|
:command:`pool init` [*pool-name*] [--force]
|
|
Initialize pool for use by RBD. Newly created pools must initialized
|
|
prior to use.
|
|
|
|
:command:`resize` (-s | --size *size-in-M/G/T*) [--allow-shrink] *image-spec*
|
|
Resize rbd image. The size parameter also needs to be specified.
|
|
The --allow-shrink option lets the size be reduced.
|
|
|
|
:command:`rm` *image-spec*
|
|
Delete an rbd image (including all data blocks). If the image has
|
|
snapshots, this fails and nothing is deleted.
|
|
|
|
:command:`snap create` *snap-spec*
|
|
Create a new snapshot. Requires the snapshot name parameter specified.
|
|
|
|
:command:`snap limit clear` *image-spec*
|
|
Remove any previously set limit on the number of snapshots allowed on
|
|
an image.
|
|
|
|
:command:`snap limit set` [--limit] *limit* *image-spec*
|
|
Set a limit for the number of snapshots allowed on an image.
|
|
|
|
:command:`snap ls` *image-spec*
|
|
Dump the list of snapshots inside a specific image.
|
|
|
|
:command:`snap protect` *snap-spec*
|
|
Protect a snapshot from deletion, so that clones can be made of it
|
|
(see `rbd clone`). Snapshots must be protected before clones are made;
|
|
protection implies that there exist dependent cloned children that
|
|
refer to this snapshot. `rbd clone` will fail on a nonprotected
|
|
snapshot.
|
|
|
|
This requires image format 2.
|
|
|
|
:command:`snap purge` *image-spec*
|
|
Remove all unprotected snapshots from an image.
|
|
|
|
:command:`snap rename` *src-snap-spec* *dest-snap-spec*
|
|
Rename a snapshot. Note: rename across pools and images is not supported.
|
|
|
|
:command:`snap rm` [--force] *snap-spec*
|
|
Remove the specified snapshot.
|
|
|
|
:command:`snap rollback` *snap-spec*
|
|
Rollback image content to snapshot. This will iterate through the entire blocks
|
|
array and update the data head content to the snapshotted version.
|
|
|
|
:command:`snap unprotect` *snap-spec*
|
|
Unprotect a snapshot from deletion (undo `snap protect`). If cloned
|
|
children remain, `snap unprotect` fails. (Note that clones may exist
|
|
in different pools than the parent snapshot.)
|
|
|
|
This requires image format 2.
|
|
|
|
:command:`status` *image-spec*
|
|
Show the status of the image, including which clients have it open.
|
|
|
|
:command:`trash ls` [*pool-name*]
|
|
List all entries from trash.
|
|
|
|
:command:`trash mv` *image-spec*
|
|
Move an image to the trash. Images, even ones actively in-use by
|
|
clones, can be moved to the trash and deleted at a later time.
|
|
|
|
:command:`trash purge` [*pool-name*]
|
|
Remove all expired images from trash.
|
|
|
|
:command:`trash restore` *image-id*
|
|
Restore an image from trash.
|
|
|
|
:command:`trash rm` *image-id*
|
|
Delete an image from trash. If image deferment time has not expired
|
|
you can not removed it unless use force. But an actively in-use by clones
|
|
or has snapshots can not be removed.
|
|
|
|
:command:`watch` *image-spec*
|
|
Watch events on image.
|
|
|
|
Image, snap, group and journal specs
|
|
====================================
|
|
|
|
| *image-spec* is [*pool-name*/]\ *image-name*
|
|
| *snap-spec* is [*pool-name*/]\ *image-name*\ @\ *snap-name*
|
|
| *group-spec* is [*pool-name*/]\ *group-name*
|
|
| *group-snap-spec* is [*pool-name*/]\ *group-name*\ @\ *snap-name*
|
|
| *journal-spec* is [*pool-name*/]\ *journal-name*
|
|
|
|
The default for *pool-name* is "rbd". If an image name contains a slash
|
|
character ('/'), *pool-name* is required.
|
|
|
|
The *journal-name* is *image-id*.
|
|
|
|
You may specify each name individually, using --pool, --image and --snap
|
|
options, but this is discouraged in favor of the above spec syntax.
|
|
|
|
Striping
|
|
========
|
|
|
|
RBD images are striped over many objects, which are then stored by the
|
|
Ceph distributed object store (RADOS). As a result, read and write
|
|
requests for the image are distributed across many nodes in the
|
|
cluster, generally preventing any single node from becoming a
|
|
bottleneck when individual images get large or busy.
|
|
|
|
The striping is controlled by three parameters:
|
|
|
|
.. option:: object-size
|
|
|
|
The size of objects we stripe over is a power of two. It will be rounded up the nearest power of two.
|
|
The default object size is 4 MB, smallest is 4K and maximum is 32M.
|
|
|
|
.. option:: stripe_unit
|
|
|
|
Each [*stripe_unit*] contiguous bytes are stored adjacently in the same object, before we move on
|
|
to the next object.
|
|
|
|
.. option:: stripe_count
|
|
|
|
After we write [*stripe_unit*] bytes to [*stripe_count*] objects, we loop back to the initial object
|
|
and write another stripe, until the object reaches its maximum size. At that point,
|
|
we move on to the next [*stripe_count*] objects.
|
|
|
|
By default, [*stripe_unit*] is the same as the object size and [*stripe_count*] is 1. Specifying a different
|
|
[*stripe_unit*] requires that the STRIPINGV2 feature be supported (added in Ceph v0.53) and format 2 images be
|
|
used.
|
|
|
|
|
|
Kernel rbd (krbd) options
|
|
=========================
|
|
|
|
Most of these options are useful mainly for debugging and benchmarking. The
|
|
default values are set in the kernel and may therefore depend on the version of
|
|
the running kernel.
|
|
|
|
Per client instance `rbd device map` options:
|
|
|
|
* fsid=aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee - FSID that should be assumed by
|
|
the client.
|
|
|
|
* ip=a.b.c.d[:p] - IP and, optionally, port the client should use.
|
|
|
|
* share - Enable sharing of client instances with other mappings (default).
|
|
|
|
* noshare - Disable sharing of client instances with other mappings.
|
|
|
|
* crc - Enable CRC32C checksumming for data writes (default).
|
|
|
|
* nocrc - Disable CRC32C checksumming for data writes.
|
|
|
|
* cephx_require_signatures - Require cephx message signing (since 3.19,
|
|
default).
|
|
|
|
* nocephx_require_signatures - Don't require cephx message signing (since
|
|
3.19).
|
|
|
|
* tcp_nodelay - Disable Nagle's algorithm on client sockets (since 4.0,
|
|
default).
|
|
|
|
* notcp_nodelay - Enable Nagle's algorithm on client sockets (since 4.0).
|
|
|
|
* cephx_sign_messages - Enable message signing (since 4.4, default).
|
|
|
|
* nocephx_sign_messages - Disable message signing (since 4.4).
|
|
|
|
* mount_timeout=x - A timeout on various steps in `rbd device map` and
|
|
`rbd device unmap` sequences (default is 60 seconds). In particular,
|
|
since 4.2 this can be used to ensure that `rbd device unmap` eventually
|
|
times out when there is no network connection to a cluster.
|
|
|
|
* osdkeepalive=x - OSD keepalive timeout (default is 5 seconds).
|
|
|
|
* osd_idle_ttl=x - OSD idle TTL (default is 60 seconds).
|
|
|
|
Per mapping (block device) `rbd device map` options:
|
|
|
|
* rw - Map the image read-write (default).
|
|
|
|
* ro - Map the image read-only. Equivalent to --read-only.
|
|
|
|
* queue_depth=x - queue depth (since 4.2, default is 128 requests).
|
|
|
|
* lock_on_read - Acquire exclusive lock on reads, in addition to writes and
|
|
discards (since 4.9).
|
|
|
|
* exclusive - Disable automatic exclusive lock transitions (since 4.12).
|
|
|
|
* lock_timeout=x - A timeout on waiting for the acquisition of exclusive lock
|
|
(since 4.17, default is 0 seconds, meaning no timeout).
|
|
|
|
* notrim - Turn off discard and write zeroes offload support to avoid
|
|
deprovisioning a fully provisioned image (since 4.17). When enabled, discard
|
|
requests will fail with -EOPNOTSUPP, write zeroes requests will fall back to
|
|
manually zeroing.
|
|
|
|
`rbd device unmap` options:
|
|
|
|
* force - Force the unmapping of a block device that is open (since 4.9). The
|
|
driver will wait for running requests to complete and then unmap; requests
|
|
sent to the driver after initiating the unmap will be failed.
|
|
|
|
|
|
Examples
|
|
========
|
|
|
|
To create a new rbd image that is 100 GB::
|
|
|
|
rbd create mypool/myimage --size 102400
|
|
|
|
To use a non-default object size (8 MB)::
|
|
|
|
rbd create mypool/myimage --size 102400 --object-size 8M
|
|
|
|
To delete an rbd image (be careful!)::
|
|
|
|
rbd rm mypool/myimage
|
|
|
|
To create a new snapshot::
|
|
|
|
rbd snap create mypool/myimage@mysnap
|
|
|
|
To create a copy-on-write clone of a protected snapshot::
|
|
|
|
rbd clone mypool/myimage@mysnap otherpool/cloneimage
|
|
|
|
To see which clones of a snapshot exist::
|
|
|
|
rbd children mypool/myimage@mysnap
|
|
|
|
To delete a snapshot::
|
|
|
|
rbd snap rm mypool/myimage@mysnap
|
|
|
|
To map an image via the kernel with cephx enabled::
|
|
|
|
rbd device map mypool/myimage --id admin --keyfile secretfile
|
|
|
|
To map an image via the kernel with different cluster name other than default *ceph*::
|
|
|
|
rbd device map mypool/myimage --cluster cluster-name
|
|
|
|
To unmap an image::
|
|
|
|
rbd device unmap /dev/rbd0
|
|
|
|
To create an image and a clone from it::
|
|
|
|
rbd import --image-format 2 image mypool/parent
|
|
rbd snap create mypool/parent@snap
|
|
rbd snap protect mypool/parent@snap
|
|
rbd clone mypool/parent@snap otherpool/child
|
|
|
|
To create an image with a smaller stripe_unit (to better distribute small writes in some workloads)::
|
|
|
|
rbd create mypool/myimage --size 102400 --stripe-unit 65536B --stripe-count 16
|
|
|
|
To change an image from one image format to another, export it and then
|
|
import it as the desired image format::
|
|
|
|
rbd export mypool/myimage@snap /tmp/img
|
|
rbd import --image-format 2 /tmp/img mypool/myimage2
|
|
|
|
To lock an image for exclusive use::
|
|
|
|
rbd lock add mypool/myimage mylockid
|
|
|
|
To release a lock::
|
|
|
|
rbd lock remove mypool/myimage mylockid client.2485
|
|
|
|
To list images from trash::
|
|
|
|
rbd trash ls mypool
|
|
|
|
To defer delete an image (use *--expires-at* to set expiration time, default is now)::
|
|
|
|
rbd trash mv mypool/myimage --expires-at "tomorrow"
|
|
|
|
To delete an image from trash (be careful!)::
|
|
|
|
rbd trash rm mypool/myimage-id
|
|
|
|
To force delete an image from trash (be careful!)::
|
|
|
|
rbd trash rm mypool/myimage-id --force
|
|
|
|
To restore an image from trash::
|
|
|
|
rbd trash restore mypool/myimage-id
|
|
|
|
To restore an image from trash and rename it::
|
|
|
|
rbd trash restore mypool/myimage-id --image mynewimage
|
|
|
|
|
|
Availability
|
|
============
|
|
|
|
**rbd** is part of Ceph, a massively scalable, open-source, distributed storage system. Please refer to
|
|
the Ceph documentation at http://ceph.com/docs for more information.
|
|
|
|
|
|
See also
|
|
========
|
|
|
|
:doc:`ceph <ceph>`\(8),
|
|
:doc:`rados <rados>`\(8)
|