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
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========
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Device-Mapper's "delay" target delays reads and/or writes
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and maps them to different devices.
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Parameters:
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<device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
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With separate write parameters, the first set is only used for reads.
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Offsets are specified in sectors.
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Delays are specified in milliseconds.
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Example scripts
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===============
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[[
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#!/bin/sh
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# Create device delaying rw operation for 500ms
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echo "0 `blockdev --getsize $1` delay $1 0 500" | dmsetup create delayed
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]]
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[[
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#!/bin/sh
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# Create device delaying only write operation for 500ms and
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# splitting reads and writes to different devices $1 $2
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echo "0 `blockdev --getsize $1` delay $1 0 0 $2 0 500" | dmsetup create delayed
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]]
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