mirror of
https://github.com/torvalds/linux.git
synced 2024-12-21 10:31:54 +00:00
f49e869a61
Only delay params are mentioned in delay.txt. Mention offsets just like documents for linear and flakey do. Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
28 lines
728 B
Plaintext
28 lines
728 B
Plaintext
dm-delay
|
|
========
|
|
|
|
Device-Mapper's "delay" target delays reads and/or writes
|
|
and maps them to different devices.
|
|
|
|
Parameters:
|
|
<device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
|
|
|
|
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
|
|
]]
|