xref: /openbmc/linux/Documentation/ABI/testing/sysfs-block-dm (revision e5451c8f8330e03ad3cfa16048b4daf961af434f)
1 What:		/sys/block/dm-<num>/dm/name
2 Date:		January 2009
3 KernelVersion:	2.6.29
4 Contact:	dm-devel@redhat.com
5 Description:	Device-mapper device name.
6 		Read-only string containing mapped device name.
7 Users:		util-linux, device-mapper udev rules
8 
9 What:		/sys/block/dm-<num>/dm/uuid
10 Date:		January 2009
11 KernelVersion:	2.6.29
12 Contact:	dm-devel@redhat.com
13 Description:	Device-mapper device UUID.
14 		Read-only string containing DM-UUID or empty string
15 		if DM-UUID is not set.
16 Users:		util-linux, device-mapper udev rules
17 
18 What:		/sys/block/dm-<num>/dm/suspended
19 Date:		June 2009
20 KernelVersion:	2.6.31
21 Contact:	dm-devel@redhat.com
22 Description:	Device-mapper device suspend state.
23 		Contains the value 1 while the device is suspended.
24 		Otherwise it contains 0. Read-only attribute.
25 Users:		util-linux, device-mapper udev rules
26 
27 What:		/sys/block/dm-<num>/dm/rq_based_seq_io_merge_deadline
28 Date:		March 2015
29 KernelVersion:	4.1
30 Contact:	dm-devel@redhat.com
31 Description:	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 
41 What:		/sys/block/dm-<num>/dm/use_blk_mq
42 Date:		March 2015
43 KernelVersion:	4.1
44 Contact:	dm-devel@redhat.com
45 Description:	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