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Commit | Line | Data |
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26b9f228 HM |
1 | dm-delay |
2 | ======== | |
3 | ||
4 | Device-Mapper's "delay" target delays reads and/or writes | |
5 | and maps them to different devices. | |
6 | ||
7 | Parameters: | |
cda6b5ab MP |
8 | <device> <offset> <delay> [<write_device> <write_offset> <write_delay> |
9 | [<flush_device> <flush_offset> <flush_delay>]] | |
26b9f228 HM |
10 | |
11 | With separate write parameters, the first set is only used for reads. | |
f49e869a | 12 | Offsets are specified in sectors. |
26b9f228 HM |
13 | Delays are specified in milliseconds. |
14 | ||
15 | Example scripts | |
16 | =============== | |
17 | [[ | |
18 | #!/bin/sh | |
19 | # Create device delaying rw operation for 500ms | |
95f21c5c | 20 | echo "0 `blockdev --getsz $1` delay $1 0 500" | dmsetup create delayed |
26b9f228 HM |
21 | ]] |
22 | ||
23 | [[ | |
24 | #!/bin/sh | |
25 | # Create device delaying only write operation for 500ms and | |
26 | # splitting reads and writes to different devices $1 $2 | |
95f21c5c | 27 | echo "0 `blockdev --getsz $1` delay $1 0 0 $2 0 500" | dmsetup create delayed |
26b9f228 | 28 | ]] |