1What:		/sys/bus/rbd/
2Date:		November 2010
3Contact:	Yehuda Sadeh <yehuda@newdream.net>,
4		Sage Weil <sage@newdream.net>
5Description:
6
7Being used for adding and removing rbd block devices.
8
9Usage: <mon ip addr> <options> <pool name> <rbd image name> [snap name]
10
11 $ echo "192.168.0.1 name=admin rbd foo" > /sys/bus/rbd/add
12
13The snapshot name can be "-" or omitted to map the image read/write. A <dev-id>
14will be assigned for any registered block device. If snapshot is used, it will
15be mapped read-only.
16
17Removal of a device:
18
19  $ echo <dev-id> > /sys/bus/rbd/remove
20
21Entries under /sys/bus/rbd/devices/<dev-id>/
22--------------------------------------------
23
24client_id
25
26	The ceph unique client id that was assigned for this specific session.
27
28features
29
30	A hexadecimal encoding of the feature bits for this image.
31
32major
33
34	The block device major number.
35
36name
37
38	The name of the rbd image.
39
40image_id
41
42	The unique id for the rbd image.  (For rbd image format 1
43	this is empty.)
44
45pool
46
47	The name of the storage pool where this rbd image resides.
48	An rbd image name is unique within its pool.
49
50pool_id
51
52	The unique identifier for the rbd image's pool.  This is
53	a permanent attribute of the pool.  A pool's id will never
54	change.
55
56size
57
58	The size (in bytes) of the mapped block device.
59
60refresh
61
62	Writing to this file will reread the image header data and set
63	all relevant datastructures accordingly.
64
65current_snap
66
67	The current snapshot for which the device is mapped.
68
69snap_*
70
71	A directory per each snapshot
72
73parent
74
75	Information identifying the pool, image, and snapshot id for
76	the parent image in a layered rbd image (format 2 only).
77
78Entries under /sys/bus/rbd/devices/<dev-id>/snap_<snap-name>
79-------------------------------------------------------------
80
81snap_id
82
83	The rados internal snapshot id assigned for this snapshot
84
85snap_size
86
87	The size of the image when this snapshot was taken.
88
89snap_features
90
91	A hexadecimal encoding of the feature bits for this snapshot.
92
93