Commit | Line | Data |
---|---|---|
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: | |
8 | <device> <offset> <delay> [<write_device> <write_offset> <write_delay>] | |
9 | ||
10 | With separate write parameters, the first set is only used for reads. | |
f49e869a | 11 | Offsets are specified in sectors. |
26b9f228 HM |
12 | Delays are specified in milliseconds. |
13 | ||
14 | Example scripts | |
15 | =============== | |
16 | [[ | |
17 | #!/bin/sh | |
18 | # Create device delaying rw operation for 500ms | |
19 | echo "0 `blockdev --getsize $1` delay $1 0 500" | dmsetup create delayed | |
20 | ]] | |
21 | ||
22 | [[ | |
23 | #!/bin/sh | |
24 | # Create device delaying only write operation for 500ms and | |
25 | # splitting reads and writes to different devices $1 $2 | |
26 | echo "0 `blockdev --getsize $1` delay $1 0 0 $2 0 500" | dmsetup create delayed | |
27 | ]] |