| ======== |
| 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> |
| [<flush_device> <flush_offset> <flush_delay>]] |
| |
| With separate write parameters, the first set is only used for reads. |
| Offsets are specified in sectors. |
| Delays are specified in milliseconds. |
| |
| Example scripts |
| =============== |
| |
| :: |
| |
| #!/bin/sh |
| # Create device delaying rw operation for 500ms |
| echo "0 `blockdev --getsz $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 --getsz $1` delay $1 0 0 $2 0 500" | dmsetup create delayed |
