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authorPaul Mackerras <paulus@samba.org>2007-05-10 21:08:37 +1000
committerPaul Mackerras <paulus@samba.org>2007-05-10 21:08:37 +1000
commit2ecf042ef530dd0943e41d84b6344f507941af3e (patch)
tree73100361dd74e3f80f14c7c81ba4675948983f44 /Documentation/device-mapper/delay.txt
parent32a56ebb24f23da1bbaf24292acf85b6c04526ab (diff)
parentde5603748af8bf7deac403e6ba92887f8d18e812 (diff)
Merge branch 'linux-2.6'
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+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
+]]