rados – rados object storage utility¶
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.
As an alternative to
--pgidalso allow users to specify the PG id to which the command will be directed. With this option, certain commands like
lsallow users to limit the scope of the command to the given PG.
- -N namespace, --namespace namespace¶
Specify the rados namespace to use for the object.
- -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, stat2, get, put, append, truncate, rm, ls and all xattr related operation
- -O object_size¶
Set the object size for put/get ops and for write benchmarking
Will set the lock cookie for acquiring advisory lock (lock get command). If the cookie is not empty, this option must be passed to lock break command to find the correct lock when releasing lock.
List object pools
Show utilization statistics, including disk usage (bytes) and object counts, over the entire system and broken down by pool.
- 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. Warning: The put command creates a single RADOS object, sized just as large as your input file. Unless your objects are of reasonable and consistent sizes, that is probably not what you want – consider using RGW/S3, CephFS, or RBD instead.
- 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 the given pool and write to outfile. Instead of
--pgidwill be specified,
lswill only list the objects in the given PG.
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.
- cleanup [ –run-name run_name ] [ –prefix prefix ]
Clean up a previous benchmark operation. Note: the default run-name is “benchmark_last_metadata”
- 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.
- stat name
Get stat (ie. mtime, size) of given object
- stat2 name
Get stat (similar to stat, but with high precision time) of given 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 is not 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 is not 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.
- export filename
Serialize pool contents to a file or standard output.n”
- import [–dry-run] [–no-overwrite] < filename | - >
Load pool contents from a file or standard input
To view cluster utilization:
To get a list object in pool foo sent to stdout:
rados -p foo ls -
To get a list of objects in PG 0.6:
rados --pgid 0.6 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.