mirror of
https://github.com/torvalds/linux.git
synced 2024-11-28 15:11:31 +00:00
26b9f22870
New device-mapper target that can delay I/O (for testing). Reads can be separated from writes, redirected to different underlying devices and delayed by differing amounts of time. Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
27 lines
694 B
Plaintext
27 lines
694 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.
|
|
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
|
|
]]
|