<builder_file> Shows information about the ring and the devices within.
search <search-value> Shows information about matching devices.
add z<zone>-<ip>:<port>/<device_name>_<meta> <weight> add r<region>z<zone>-<ip>:<port>/<device_name>_<meta> <weight> add -r <region> -z <zone> -i <ip> -p <port> -d <device_name> -m <meta> -w <weight> Adds a device to the ring with the given information. No partitions will be assigned to the new device until after running rebalance. This is so you can make multiple device changes and rebalance them all just once.
create <part_power> <replicas> <min_part_hours> Creates <builder_file> with 2^<part_power> partitions and <replicas>. <min_part_hours> is number of hours to restrict moving a partition more than once.
list_parts <search-value> [<search-value>] .. Returns a 2 column list of all the partitions that are assigned to any of the devices matching the search values given. The first column is the assigned partition number and the second column is the number of device matches for that partition. The list is ordered from most number of matches to least. If there are a lot of devices to match against, this command could take a while to run.
rebalence Attempts to rebalance the ring by reassigning partitions that havent been recently reassigned.
remove <search-value> Removes the device(s) from the ring. This should normally just be used for a device that has failed. For a device you wish to decommission, its best to set its weight to 0, wait for it to drain all its data, then use this remove command. This will not take effect until after running rebalance. This is so you can make multiple device changes and rebalance them all just once.
set_info <search-value> <ip>:<port>/<device_name>_<meta> Resets the devices information. This information isnt used to assign partitions, so you can use write_ring afterward to rewrite the current ring with the newer device information. Any of the parts are optional in the final <ip>:<port>/<device_name>_<meta> parameter; just give what you want to change. For instance set_info d74 _"snet: 220.127.116.11" would just update the meta data for device id 74.
set_min_part_hours <hours> Changes the <min_part_hours> to the given <hours>. This should be set to however long a full replication/update cycle takes. Were working on a way to determine this more easily than scanning logs.
set_weight <search-value> <weight> Resets the devices weight. No partitions will be reassigned to or from the device until after running rebalance. This is so you can make multiple device changes and rebalance them all just once.
validate Just runs the validation routines on the ring.
write_ring Just rewrites the distributable ring file. This is done automatically after a successful rebalance, so really this is only useful after one or more set_info calls when no rebalance is needed but you want to send out the new device information.
Quick list: add create list_parts rebalance remove search set_info
set_min_part_hours set_weight validate write_ring
Exit codes: 0 = ring changed, 1 = ring did not change, 2 = error
More in depth documentation about the swift ring and also Openstack-Swift as a whole can be found at http://swift.openstack.org/overview_ring.html, http://swift.openstack.org/admin_guide.html#managing-the-rings and http://swift.openstack.org