chen@admin-node:~$ rbd --help
usage: rbd [-n <auth user>] [OPTIONS] <cmd> ...
where 'pool' is a rados pool name (default is 'rbd') and 'cmd' is one of:
(ls | list) [-l | --long ] [pool-name] list rbd images
(-l includes snapshots/clones)
info <image-name> show information about image size,
striping, etc.
create [--order <bits>] [--image-features <features>] [--image-shared]
--size <MB> <name> create an empty image
clone [--order <bits>] [--image-features <features>] [--image-shared]
<parentsnap> <clonename> clone a snapshot into a COW
child image
children <snap-name> display children of snapshot
flatten <image-name> fill clone with parent data
(make it independent)
resize --size <MB> <image-name> resize (expand or contract) image
rm <image-name> delete an image
export <image-name> <path> export image to file
"-" for stdout
import [--image-features <features>] [--image-shared]
<path> <image-name> import image from file (dest
defaults as the filename part
of file). "-" for stdin
diff <image-name> [--from-snap <snap-name>] print extents that differ since
a previous snap, or image creation
export-diff <image-name> [--from-snap <snap-name>] <path>
export an incremental diff to
path, or "-" for stdout
merge-diff <diff1> <diff2> <path> merge <diff1> and <diff2> into
<path>, <diff1> could be "-"
for stdin, and <path> could be "-"
for stdout
import-diff <path> <image-name> import an incremental diff from
path or "-" for stdin
(cp | copy) <src> <dest> copy src image to dest
(mv | rename) <src> <dest> rename src image to dest
snap ls <image-name> dump list of image snapshots
snap create <snap-name> create a snapshot
snap rollback <snap-name> rollback image to snapshot
snap rm <snap-name> deletes a snapshot
snap purge <image-name> deletes all snapshots
snap protect <snap-name> prevent a snapshot from being deleted
snap unprotect <snap-name> allow a snapshot to be deleted
watch <image-name> watch events on image
status <image-name> show the status of this image
map <image-name> map image to a block device
using the kernel
unmap <device> unmap a rbd device that was
mapped by the kernel
showmapped show the rbd images mapped
by the kernel
lock list <image-name> show locks held on an image
lock add <image-name> <id> [--shared <tag>] take a lock called id on an image
lock remove <image-name> <id> <locker> release a lock on an image
bench-write <image-name> simple write benchmark
--io-size <bytes> write size
--io-threads <num> ios in flight
--io-total <bytes> total bytes to write
--io-pattern <seq|rand> write pattern <image-name>, <snap-name> are [pool/]name[@snap], or you may specify
individual pieces of names with -p/--pool, --image, and/or --snap. Other input options:
-p, --pool <pool> source pool name
--image <image-name> image name
--dest <image-name> destination [pool and] image name
--snap <snap-name> snapshot name
--dest-pool <name> destination pool name
--path <path-name> path name for import/export
--size <size in MB> size of image for create and resize
--order <bits> the object size in bits; object size will be
( << order) bytes. Default is ( MB).
--image-format <format-number> format to use when creating an image
format is the original format (default)
format supports cloning
--image-features <features> optional format features to enable
+ layering support, + striping v2,
+ exclusive lock, + object map
--image-shared image will be used concurrently (disables
RBD exclusive lock and dependent features)
--stripe-unit <size-in-bytes> size (in bytes) of a block of data
--stripe-count <num> number of consecutive objects in a stripe
--id <username> rados user (without 'client.'prefix) to
authenticate as
--keyfile <path> file containing secret key for use with cephx
--shared <tag> take a shared (rather than exclusive) lock
--format <output-format> output format (default: plain, json, xml)
--pretty-format make json or xml output more readable
--no-progress do not show progress for long-running commands
-o, --options <map-options> options to use when mapping an image
--read-only set device readonly when mapping image
--allow-shrink allow shrinking of an image when resizing