rados man page

rados — rados object storage utility


rados [ -m monaddr ] [ mkpool | rmpool foo ] [ -p | –pool
pool ] [ -s | –snap snap ] [ -i infile ] [ -o outfile ]


rados is a utility for interacting with a Ceph object storage cluster (RADOS), part of the Ceph distributed storage system.


-p pool, --pool pool

Interact with the given pool. Required by most commands.

-s snap, --snap snap

Read from the given pool snapshot. Valid for all pool-specific read operations.

-i infile

will specify an input file to be passed along as a payload with the command to the monitor cluster. This is only used for specific monitor commands.

-o outfile

will write any payload returned by the monitor cluster with its reply to outfile. Only specific monitor commands (e.g. osd getmap) return a payload.

-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).

-b block_size

Set the block size for put/get/append ops and for write benchmarking.


Uses the striping API of rados rather than the default one. Available for stat, get, put, append, truncate, rm, ls and all xattr related operation

Global Commands


List object pools


Show utilization statistics, including disk usage (bytes) and object counts, over the entire system and broken down by pool.

mkpool foo

Create a pool with name foo.

rmpool foo [ foo –yes-i-really-really-mean-it ]

Delete the pool foo (and all its data).

list-inconsistent-pg pool

List inconsistent PGs in given pool.

list-inconsistent-obj pgid

List inconsistent objects in given PG.

list-inconsistent-snapset pgid

List inconsistent snapsets in given PG.

Pool Specific Commands

get name outfile

Read object name from the cluster and write it to outfile.

put name infile [–offset offset]

Write object name with start offset (default:0) to the cluster with contents from infile.

append name infile

Append object name to the cluster with contents from infile.

rm name

Remove object name.

listwatchers name

List the watchers of object name.

ls outfile

List objects in given pool and write to outfile.


List snapshots for given pool.

clonedata srcname dstname –object-locator key

Clone object byte data from srcname to dstname.  Both objects must be stored with the locator key key (usually either srcname or dstname).  Object attributes and omap keys are not copied or cloned.

mksnap foo

Create pool snapshot named foo.

rmsnap foo

Remove pool snapshot named foo.

bench seconds mode [ -b objsize ] [ -t threads ]

Benchmark for seconds. The mode can be write, seq, or rand. seq and rand are read benchmarks, either sequential or random. Before running one of the reading benchmarks, run a write benchmark with the –no-cleanup option. The default object size is 4 MB, and the default number of simulated threads (parallel writes) is 16. The –run-name <label> option is useful for benchmarking a workload test from multiple clients. The <label> is an arbitrary object name. It is “benchmark_last_metadata” by default, and is used as the underlying object name for “read” and “write” ops. Note: -b objsize option is valid only in write mode. Note: write and seq must be run on the same host otherwise the objects created by write will have names that will fail seq.


listxattr name

List all extended attributes of an object.

getxattr name attr

Dump the extended attribute value of attr of an object.

setxattr name attr value

Set the value of attr in the extended attributes of an object.

rmxattr name attr

Remove attr from the extended attributes of an object.

listomapkeys name

List all the keys stored in the object map of object name.

listomapvals name

List all key/value pairs stored in the object map of object name. The values are dumped in hexadecimal.

getomapval [ –omap-key-file file ] name key [ out-file ]

Dump the hexadecimal value of key in the object map of object name. If the optional out-file argument isn’t provided, the value will be written to standard output.

setomapval [ –omap-key-file file ] name key [ value ]

Set the value of key in the object map of object name. If the optional value argument isn’t provided, the value will be read from standard input.

rmomapkey [ –omap-key-file file ] name key

Remove key from the object map of object name.

getomapheader name

Dump the hexadecimal value of the object map header of object name.

setomapheader name value

Set the value of the object map header of object name.


To view cluster utilization:

rados df

To get a list object in pool foo sent to stdout:

rados -p foo ls -

To write an object:

rados -p foo put myobject blah.txt

To create a snapshot:

rados -p foo mksnap mysnap

To delete the object:

rados -p foo rm myobject

To read a previously snapshotted version of an object:

rados -p foo -s mysnap get myobject blah.txt.old

To list inconsistent objects in PG 0.6:

rados list-inconsistent-obj 0.6 --format=json-pretty


rados 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


Referenced By

librados-config(8), rbd(8).

Jul 23, 2017 dev Ceph