1*6cf2a73cSMauro Carvalho Chehab======== 2*6cf2a73cSMauro Carvalho Chehabdm-delay 3*6cf2a73cSMauro Carvalho Chehab======== 4*6cf2a73cSMauro Carvalho Chehab 5*6cf2a73cSMauro Carvalho ChehabDevice-Mapper's "delay" target delays reads and/or writes 6*6cf2a73cSMauro Carvalho Chehaband maps them to different devices. 7*6cf2a73cSMauro Carvalho Chehab 8*6cf2a73cSMauro Carvalho ChehabParameters:: 9*6cf2a73cSMauro Carvalho Chehab 10*6cf2a73cSMauro Carvalho Chehab <device> <offset> <delay> [<write_device> <write_offset> <write_delay> 11*6cf2a73cSMauro Carvalho Chehab [<flush_device> <flush_offset> <flush_delay>]] 12*6cf2a73cSMauro Carvalho Chehab 13*6cf2a73cSMauro Carvalho ChehabWith separate write parameters, the first set is only used for reads. 14*6cf2a73cSMauro Carvalho ChehabOffsets are specified in sectors. 15*6cf2a73cSMauro Carvalho ChehabDelays are specified in milliseconds. 16*6cf2a73cSMauro Carvalho Chehab 17*6cf2a73cSMauro Carvalho ChehabExample scripts 18*6cf2a73cSMauro Carvalho Chehab=============== 19*6cf2a73cSMauro Carvalho Chehab 20*6cf2a73cSMauro Carvalho Chehab:: 21*6cf2a73cSMauro Carvalho Chehab 22*6cf2a73cSMauro Carvalho Chehab #!/bin/sh 23*6cf2a73cSMauro Carvalho Chehab # Create device delaying rw operation for 500ms 24*6cf2a73cSMauro Carvalho Chehab echo "0 `blockdev --getsz $1` delay $1 0 500" | dmsetup create delayed 25*6cf2a73cSMauro Carvalho Chehab 26*6cf2a73cSMauro Carvalho Chehab:: 27*6cf2a73cSMauro Carvalho Chehab 28*6cf2a73cSMauro Carvalho Chehab #!/bin/sh 29*6cf2a73cSMauro Carvalho Chehab # Create device delaying only write operation for 500ms and 30*6cf2a73cSMauro Carvalho Chehab # splitting reads and writes to different devices $1 $2 31*6cf2a73cSMauro Carvalho Chehab echo "0 `blockdev --getsz $1` delay $1 0 0 $2 0 500" | dmsetup create delayed 32