Provided by: ceph-common_0.41-1ubuntu2_amd64
rbd - manage rados block device (RBD) images
rbd [ -c ceph.conf ] [ -m monaddr ] [ -p | --pool pool ] [ --size size ] [ --order bits ] [ command ... ]
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.
-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. -m monaddress[:port] Connect to specified monitor (instead of looking through ceph.conf). -p pool, --pool pool Interact with the given pool. Required by most commands.
--size size-in-mb Specifies the size (in megabytes) of the new rbd image. --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). --snap snap Specifies the snapshot name for the specific operation. --user username Specifies the username to use with the map command. --secret filename Specifies a file containing the secret to use with the map command.
ls [pool-name] Will list all rbd images listed in the rbd_directory object. info [image-name] Will dump information (such as size and order) about a specific rbd image. create [image-name] Will create a new rbd image. You must also specify the size via --size. resize [image-name] Resizes rbd image. The size parameter also needs to be specified. rm [image-name] Deletes an rbd image (including all data blocks). If the image has snapshots, this fails and nothing is deleted. export [image-name] [dest-path] Exports image to dest path. import [path] [dest-image] Creates a new image and imports its data from path. cp [src-image] [dest-image] Copies the content of a src-image into the newly created dest-image. mv [src-image] [dest-image] Renames an image. snap ls [image-name] Dumps the list of snapshots inside a specific image. snap create [image-name] Creates a new snapshot. Requires the snapshot name parameter specified. 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. snap rm [image-name] Removes the specified snapshot. snap purge [image-name] Removes all snapshots from an image. map [image-name] Maps the specified image to a block device via the rbd kernel module. unmap [device-path] Unmaps the block device that was mapped via the rbd kernel module. showmapped Show the rbd images that are mapped via the rbd kernel module.
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.
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 create mypool/myimage@mysnap To map an image via the kernel with cephx enabled: rbd map myimage --user admin --secret secretfile To unmap an image: rbd unmap /dev/rbd0
rbd is part of the Ceph distributed file system. Please refer to the Ceph wiki at http://ceph.newdream.net/wiki for more information.
2011, New Dream Network