0001 What: /sys/block/dm-<num>/dm/name
0002 Date: January 2009
0003 KernelVersion: 2.6.29
0004 Contact: dm-devel@redhat.com
0005 Description: Device-mapper device name.
0006 Read-only string containing mapped device name.
0007 Users: util-linux, device-mapper udev rules
0008
0009 What: /sys/block/dm-<num>/dm/uuid
0010 Date: January 2009
0011 KernelVersion: 2.6.29
0012 Contact: dm-devel@redhat.com
0013 Description: Device-mapper device UUID.
0014 Read-only string containing DM-UUID or empty string
0015 if DM-UUID is not set.
0016 Users: util-linux, device-mapper udev rules
0017
0018 What: /sys/block/dm-<num>/dm/suspended
0019 Date: June 2009
0020 KernelVersion: 2.6.31
0021 Contact: dm-devel@redhat.com
0022 Description: Device-mapper device suspend state.
0023 Contains the value 1 while the device is suspended.
0024 Otherwise it contains 0. Read-only attribute.
0025 Users: util-linux, device-mapper udev rules
0026
0027 What: /sys/block/dm-<num>/dm/rq_based_seq_io_merge_deadline
0028 Date: March 2015
0029 KernelVersion: 4.1
0030 Contact: dm-devel@redhat.com
0031 Description: Allow control over how long a request that is a
0032 reasonable merge candidate can be queued on the request
0033 queue. The resolution of this deadline is in
0034 microseconds (ranging from 1 to 100000 usecs).
0035 Setting this attribute to 0 (the default) will disable
0036 request-based DM's merge heuristic and associated extra
0037 accounting. This attribute is not applicable to
0038 bio-based DM devices so it will only ever report 0 for
0039 them.
0040
0041 What: /sys/block/dm-<num>/dm/use_blk_mq
0042 Date: March 2015
0043 KernelVersion: 4.1
0044 Contact: dm-devel@redhat.com
0045 Description: Request-based Device-mapper blk-mq I/O path mode.
0046 Contains the value 1 if the device is using blk-mq.
0047 Otherwise it contains 0. Read-only attribute.
