Kernel-3.10.0-957.el7_delay

dm-delay

Device-Mapper’s “delay” target delays reads and/or writes
and maps them to different devices.

Parameters:
[ ]

With separate write parameters, the first set is only used for reads.
Offsets are specified in sectors.
Delays are specified in milliseconds.

Example scripts

[[
#!/bin/sh

Create device delaying rw operation for 500ms

echo “0 blockdev --getsize $1 delay $1 0 500” | dmsetup create delayed
]]

[[
#!/bin/sh

Create device delaying only write operation for 500ms and

splitting reads and writes to different devices $1 $2

echo “0 blockdev --getsize $1 delay $1 0 0 $2 0 500” | dmsetup create delayed
]]