swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
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Tip revision: fec6c6fec3e20637bee5d276fb61dd8b49a3f9cc authored by Linus Torvalds on 04 March 2009, 01:05:22 UTC
Linux 2.6.29-rc7
Tip revision: fec6c6f
delay.txt
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.
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
]]
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