DM_TARGET_DELAY(4)

NAME
dm_target_delay - Device-mapper delay target

SYNOPSIS
To compile this driver into the kernel, place the following lines in your kernel configuration file:

device dm
device dm_target_delay

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

    dm_target_delay_load="YES"

DESCRIPTION
The dm_target_delay target for dm(4) provides I/O delay for read or both read and write, and maps them to specified devices, compatible with Linux dm-delay. “dmsetup create” takes the following list of parameters for the dm_target_delay table.

<read_device> <read_offset> <read_delay> [<write_device> <write_offset> <write_delay>]

Parameters for write delay are optional. If write parameters are not specified, read parameters are used for write. In order to only delay read, explicitly specify 0 delay for write.

Offsets are specified in 512 bytes sectors. Delays are specified in milliseconds.

SEE ALSO
dm(4), dmsetup(8)

HISTORY
The dm_target_delay dm(4) target first appeared in DragonFly 4.3.

AUTHORS
Tomohiro Kusumi <tkusumi@netbsd.org>