Documentation/ABI/testing/sysfs-block-dm

   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.