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
28major
29
30	The block device major number.
31
32name
33
34	The name of the rbd image.
35
36pool
37
38	The name of the storage pool where this rbd image resides.
39	An rbd image name is unique within its pool.
40
41pool_id
42
43	The unique identifier for the rbd image's pool.  This is
44	a permanent attribute of the pool.  A pool's id will never
45	change.
46
47size
48
49	The size (in bytes) of the mapped block device.
50
51refresh
52
53	Writing to this file will reread the image header data and set
54	all relevant datastructures accordingly.
55
56current_snap
57
58	The current snapshot for which the device is mapped.
59
60create_snap
61
62	Create a snapshot:
63
64	 $ echo <snap-name> > /sys/bus/rbd/devices/<dev-id>/snap_create
65
66snap_*
67
68	A directory per each snapshot
69
70
71Entries under /sys/bus/rbd/devices/<dev-id>/snap_<snap-name>
72-------------------------------------------------------------
73
74snap_id
75
76	The rados internal snapshot id assigned for this snapshot
77
78snap_size
79
80	The size of the image when this snapshot was taken.
81
82
83