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diff --git a/man/8/rbd.rst b/man/8/rbd.rst deleted file mode 100644 index 3d917189f58..00000000000 --- a/man/8/rbd.rst +++ /dev/null @@ -1,490 +0,0 @@ -=============================================== - rbd -- manage rados block device (RBD) images -=============================================== - -.. program:: rbd - -Synopsis -======== - -| **rbd** [ -c *ceph.conf* ] [ -m *monaddr* ] [ -p | --pool *pool* ] [ - --size *size* ] [ --order *bits* ] [ *command* ... ] - - -Description -=========== - -**rbd** is a utility for manipulating rados block device (RBD) images, -used by the Linux rbd driver and the rbd storage driver for Qemu/KVM. -RBD images are simple block devices that are striped over objects and -stored in a RADOS object store. The size of the objects the image is -striped over must be a power of two. - - -Options -======= - -.. option:: -c ceph.conf, --conf ceph.conf - - Use ceph.conf configuration file instead of the default /etc/ceph/ceph.conf to - determine monitor addresses during startup. - -.. option:: -m monaddress[:port] - - Connect to specified monitor (instead of looking through ceph.conf). - -.. option:: -p pool, --pool pool - - Interact with the given pool. Required by most commands. - -.. option:: --no-progress - - Do not output progress information (goes to standard error by - default for some commands). - - -Parameters -========== - -.. option:: --image-format format - - Specifies which object layout to use. The default is 1. - - * format 1 - Use the original format for a new rbd image. This format is - understood by all versions of librbd and the kernel rbd module, but - does not support newer features like cloning. - - * format 2 - Use the second rbd format, which is supported by - librbd and kernel since version 3.11 (except for striping). This adds - support for cloning and is more easily extensible to allow more - features in the future. - -.. option:: --size size-in-mb - - Specifies the size (in megabytes) of the new rbd image. - -.. option:: --order bits - - Specifies the object size expressed as a number of bits, such that - the object size is ``1 << order``. The default is 22 (4 MB). - -.. option:: --stripe-unit size-in-bytes - - Specifies the stripe unit size in bytes. See striping section (below) for more details. - -.. option:: --stripe-count num - - Specifies the number of objects to stripe over before looping back - to the first object. See striping section (below) for more details. - -.. option:: --snap snap - - Specifies the snapshot name for the specific operation. - -.. option:: --id username - - Specifies the username (without the ``client.`` prefix) to use with the map command. - -.. option:: --keyfile filename - - Specifies a file containing the secret to use with the map command. - If not specified, ``client.admin`` will be used by default. - -.. option:: --keyring filename - - Specifies a keyring file containing a secret for the specified user - to use with the map command. If not specified, the default keyring - locations will be searched. - -.. option:: --shared tag - - Option for `lock add` that allows multiple clients to lock the - same image if they use the same tag. The tag is an arbitrary - string. This is useful for situations where an image must - be open from more than one client at once, like during - live migration of a virtual machine, or for use underneath - a clustered filesystem. - -.. option:: --format format - - Specifies output formatting (default: plain, json, xml) - -.. option:: --pretty-format - - Make json or xml formatted output more human-readable. - -.. option:: -o map-options, --options map-options - - Specifies which options to use when mapping an image. map-options is - a comma-separated string of options (similar to mount(8) mount options). - See map options section below for more details. - -.. option:: --read-only - - Map the image read-only. Equivalent to -o ro. - -.. option:: --image-feature feature - - Specifies which RBD format 2 feature should be enabled when creating - an image. Multiple features can be enabled by repeating this option - multiple times. The following features are supported: - - layering: layering support - striping: striping v2 support - exclusive-lock: exclusive locking support - object-map: object map support (requires exclusive-lock) - -.. option:: --image-shared - - Specifies that the image will be used concurrently by multiple clients. - This will disable features that are dependent upon exclusive ownership - of the image. - -Commands -======== - -.. TODO rst "option" directive seems to require --foo style options, parsing breaks on subcommands.. the args show up as bold too - -:command:`ls` [-l | --long] [pool-name] - Will list all rbd images listed in the rbd_directory object. With - -l, also show snapshots, and use longer-format output including - size, parent (if clone), format, etc. - -:command:`info` [*image-name*] - Will dump information (such as size and order) about a specific rbd image. - If image is a clone, information about its parent is also displayed. - If a snapshot is specified, whether it is protected is shown as well. - -:command:`create` [*image-name*] - Will create a new rbd image. You must also specify the size via --size. The - --stripe-unit and --stripe-count arguments are optional, but must be used together. - -:command:`clone` [*parent-snapname*] [*image-name*] - Will create a clone (copy-on-write child) of the parent snapshot. - Object order will be identical to that of the parent image unless - specified. Size will be the same as the parent snapshot. The --stripe-unit - and --stripe-count arguments are optional, but must be used together. - - The parent snapshot must be protected (see `rbd snap protect`). - This requires image format 2. - -:command:`flatten` [*image-name*] - If image is a clone, copy all shared blocks from the parent snapshot and - make the child independent of the parent, severing the link between - parent snap and child. The parent snapshot can be unprotected and - deleted if it has no further dependent clones. - - This requires image format 2. - -:command:`children` [*image-name*] - List the clones of the image at the given snapshot. This checks - every pool, and outputs the resulting poolname/imagename. - - This requires image format 2. - -:command:`resize` [*image-name*] [--allow-shrink] - Resizes rbd image. The size parameter also needs to be specified. - The --allow-shrink option lets the size be reduced. - -:command:`rm` [*image-name*] - Deletes an rbd image (including all data blocks). If the image has - snapshots, this fails and nothing is deleted. - -:command:`export` [*image-name*] [*dest-path*] - Exports image to dest path (use - for stdout). - -:command:`import` [*path*] [*dest-image*] - Creates a new image and imports its data from path (use - for - stdin). The import operation will try to create sparse rbd images - if possible. For import from stdin, the sparsification unit is - the data block size of the destination image (1 << order). - - The --stripe-unit and --stripe-count arguments are optional, but must be - used together. - -:command:`export-diff` [*image-name*] [*dest-path*] [--from-snap *snapname*] - Exports an incremental diff for an image to dest path (use - for stdout). If - an initial snapshot is specified, only changes since that snapshot are included; otherwise, - any regions of the image that contain data are included. The end snapshot is specified - using the standard --snap option or @snap syntax (see below). The image diff format includes - metadata about image size changes, and the start and end snapshots. It efficiently represents - discarded or 'zero' regions of the image. - -:command:`merge-diff` [*first-diff-path*] [*second-diff-path*] [*merged-diff-path*] - Merge two continuous incremental diffs of an image into one single diff. The - first diff's end snapshot must be equal with the second diff's start snapshot. - The first diff could be - for stdin, and merged diff could be - for stdout, which - enables multiple diff files to be merged using something like - 'rbd merge-diff first second - | rbd merge-diff - third result'. Note this command - currently only support the source incremental diff with stripe_count == 1 - -:command:`import-diff` [*src-path*] [*image-name*] - Imports an incremental diff of an image and applies it to the current image. If the diff - was generated relative to a start snapshot, we verify that snapshot already exists before - continuing. If there was an end snapshot we verify it does not already exist before - applying the changes, and create the snapshot when we are done. - -:command:`diff` [*image-name*] [--from-snap *snapname*] - Dump a list of byte extents in the image that have changed since the specified start - snapshot, or since the image was created. Each output line includes the starting offset - (in bytes), the length of the region (in bytes), and either 'zero' or 'data' to indicate - whether the region is known to be zeros or may contain other data. - -:command:`cp` [*src-image*] [*dest-image*] - Copies the content of a src-image into the newly created dest-image. - dest-image will have the same size, order, and image format as src-image. - -:command:`mv` [*src-image*] [*dest-image*] - Renames an image. Note: rename across pools is not supported. - -:command:`image-meta list` [*image-name*] - Show metadata held on the image. The first column is the key - and the second column is the value. - -:command:`image-meta get` [*image-name*] [*key*] - Get metadata value with the key. - -:command:`image-meta set` [*image-name*] [*key*] [*value*] - Set metadata key with the value. They will displayed in `metadata-list` - -:command:`image-meta remove` [*image-name*] [*key*] - Remove metadata key with the value. - -:command:`snap` ls [*image-name*] - Dumps the list of snapshots inside a specific image. - -:command:`snap` create [*image-name*] - Creates a new snapshot. Requires the snapshot name parameter specified. - -:command:`snap` rollback [*image-name*] - 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` rm [*image-name*] - Removes the specified snapshot. - -:command:`snap` purge [*image-name*] - Removes all snapshots from an image. - -:command:`snap` protect [*image-name*] - 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` unprotect [*image-name*] - 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:`map` [*image-name*] [-o | --options *map-options* ] [--read-only] - Maps the specified image to a block device via the rbd kernel module. - -:command:`unmap` [*device-path*] - Unmaps the block device that was mapped via the rbd kernel module. - -:command:`showmapped` - Show the rbd images that are mapped via the rbd kernel module. - -:command:`status` [*image-name*] - Show the status of the image, including which clients have it open. - -:command:`feature` disable [*image-name*] [*feature*] - Disables the specified feature on the specified image. Multiple features can - be specified. - -:command:`feature` enable [*image-name*] [*feature*] - Enables the specified feature on the specified image. Multiple features can - be specified. - -:command:`lock` list [*image-name*] - Show locks held on the image. The first column is the locker - to use with the `lock remove` command. - -:command:`lock` add [*image-name*] [*lock-id*] - Lock an image. The lock-id is an arbitrary name for the user's - convenience. By default, this is an exclusive lock, meaning it - will fail if the image is already locked. The --shared option - changes this behavior. Note that locking does not affect - any operation other than adding a lock. It does not - protect an image from being deleted. - -:command:`lock` remove [*image-name*] [*lock-id*] [*locker*] - Release a lock on an image. The lock id and locker are - as output by lock ls. - -:command:`bench-write` [*image-name*] --io-size [*io-size-in-bytes*] --io-threads [*num-ios-in-flight*] --io-total [*total-bytes-to-write*] - Generate a series of sequential writes to the image and measure the - write throughput and latency. Defaults are: --io-size 4096, --io-threads 16, - --io-total 1GB - -Image name -========== - -In addition to using the --pool and the --snap options, the image name can include both -the pool name and the snapshot name. The image name format is as follows:: - - [pool/]image-name[@snap] - -Thus an image name that contains a slash character ('/') requires specifying the pool -name explicitly. - - -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:: order - - The size of objects we stripe over is a power of two, specifically 2^[*order*] bytes. The default - is 22, or 4 MB. - -.. 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 (as specified by [*order*]. 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. - - -Map 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. - -* 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, i.e. MSG_AUTH - feature bit (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). - -* osdkeepalive=x - OSD keepalive timeout (default is 5 seconds). - -* osd_idle_ttl=x - OSD idle TTL (default is 60 seconds). - -* rw - Map the image read-write (default). - -* ro - Map the image read-only. Equivalent to --read-only. - - -Examples -======== - -To create a new rbd image that is 100 GB:: - - rbd -p mypool create myimage --size 102400 - -or alternatively:: - - rbd create mypool/myimage --size 102400 - -To use a non-default object size (8 MB):: - - rbd create mypool/myimage --size 102400 --order 23 - -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 map mypool/myimage --id admin --keyfile secretfile - -To unmap an image:: - - rbd unmap /dev/rbd0 - -To create an image and a clone from it:: - - rbd import --image-format 2 image mypool/parent - rbd snap create --snap snapname mypool/parent - 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 -p mypool create myimage --size 102400 --stripe-unit 65536 --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 - - -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) |