1What:		/sys/block/dm-<num>/dm/name
2Date:		January 2009
3KernelVersion:	2.6.29
4Contact:	[email protected]
5Description:	Device-mapper device name.
6		Read-only string containing mapped device name.
7Users:		util-linux, device-mapper udev rules
8
9What:		/sys/block/dm-<num>/dm/uuid
10Date:		January 2009
11KernelVersion:	2.6.29
12Contact:	[email protected]
13Description:	Device-mapper device UUID.
14		Read-only string containing DM-UUID or empty string
15		if DM-UUID is not set.
16Users:		util-linux, device-mapper udev rules
17
18What:		/sys/block/dm-<num>/dm/suspended
19Date:		June 2009
20KernelVersion:	2.6.31
21Contact:	[email protected]
22Description:	Device-mapper device suspend state.
23		Contains the value 1 while the device is suspended.
24		Otherwise it contains 0. Read-only attribute.
25Users:		util-linux, device-mapper udev rules
26
27What:		/sys/block/dm-<num>/dm/rq_based_seq_io_merge_deadline
28Date:		March 2015
29KernelVersion:	4.1
30Contact:	[email protected]
31Description:	Allow control over how long a request that is a
32		reasonable merge candidate can be queued on the request
33		queue.  The resolution of this deadline is in
34		microseconds (ranging from 1 to 100000 usecs).
35		Setting this attribute to 0 (the default) will disable
36		request-based DM's merge heuristic and associated extra
37		accounting.  This attribute is not applicable to
38		bio-based DM devices so it will only ever report 0 for
39		them.
40
41What:		/sys/block/dm-<num>/dm/use_blk_mq
42Date:		March 2015
43KernelVersion:	4.1
44Contact:	[email protected]
45Description:	Request-based Device-mapper blk-mq I/O path mode.
46		Contains the value 1 if the device is using blk-mq.
47		Otherwise it contains 0. Read-only attribute.
48