Based on kernel version 4.16.1. Page generated on 2018-04-09 11:52 EST.
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. 11 Offsets are specified in sectors. 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 --getsz $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 --getsz $1` delay $1 0 0 $2 0 500" | dmsetup create delayed 27 ]]