| 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 | 
 | ]] |