What: /sys/block/dm-<num>/dm/name
Date: January 2009
KernelVersion: 2.6.29
Contact: [email protected]
Description: Device-mapper device name.
Read-only string containing mapped device name.
Users: util-linux, device-mapper udev rules
What: /sys/block/dm-<num>/dm/uuid
Date: January 2009
KernelVersion: 2.6.29
Contact: [email protected]
Description: Device-mapper device UUID.
Read-only string containing DM-UUID or empty string
if DM-UUID is not set.
Users: util-linux, device-mapper udev rules
What: /sys/block/dm-<num>/dm/suspended
Date: June 2009
KernelVersion: 2.6.31
Contact: [email protected]
Description: Device-mapper device suspend state.
Contains the value 1 while the device is suspended.
Otherwise it contains 0. Read-only attribute.
Users: util-linux, device-mapper udev rules
What: /sys/block/dm-<num>/dm/rq_based_seq_io_merge_deadline
Date: March 2015
KernelVersion: 4.1
Contact: [email protected]
Description: Allow control over how long a request that is a
reasonable merge candidate can be queued on the request
queue. The resolution of this deadline is in
microseconds (ranging from 1 to 100000 usecs).
Setting this attribute to 0 (the default) will disable
request-based DM's merge heuristic and associated extra
accounting. This attribute is not applicable to
bio-based DM devices so it will only ever report 0 for
them.
What: /sys/block/dm-<num>/dm/use_blk_mq
Date: March 2015
KernelVersion: 4.1
Contact: [email protected]
Description: Request-based Device-mapper blk-mq I/O path mode.
Contains the value 1 if the device is using blk-mq.
Otherwise it contains 0. Read-only attribute.
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