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