xref: /dflybsd-src/share/man/man4/dm_target_delay.4 (revision b0a9540a74bf0068ba798f91d02dbab25eed2b90)
1ce4dc2f7STomohiro Kusumi.\" Copyright (c) 2015 The DragonFly BSD Project.
2ce4dc2f7STomohiro Kusumi.\" All rights reserved.
3ce4dc2f7STomohiro Kusumi.\"
4ce4dc2f7STomohiro Kusumi.\" This code is derived from software contributed to The DragonFly BSD Project
5*b0a9540aSTomohiro Kusumi.\" by Tomohiro Kusumi <tkusumi@netbsd.org>
6ce4dc2f7STomohiro Kusumi.\"
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27ce4dc2f7STomohiro Kusumi.Dd October 11, 2015
28ce4dc2f7STomohiro Kusumi.Dt DM_TARGET_DELAY 4
29ce4dc2f7STomohiro Kusumi.Os
30ce4dc2f7STomohiro Kusumi.Sh NAME
31ce4dc2f7STomohiro Kusumi.Nm dm_target_delay
32ce4dc2f7STomohiro Kusumi.Nd Device-mapper delay target
33ce4dc2f7STomohiro Kusumi.Sh SYNOPSIS
34ce4dc2f7STomohiro KusumiTo compile this driver into the kernel,
35ce4dc2f7STomohiro Kusumiplace the following lines in your
36ce4dc2f7STomohiro Kusumikernel configuration file:
37ce4dc2f7STomohiro Kusumi.Bd -ragged -offset indent
38ce4dc2f7STomohiro Kusumi.Cd "device dm"
39ce4dc2f7STomohiro Kusumi.Cd "device dm_target_delay"
40ce4dc2f7STomohiro Kusumi.Ed
41ce4dc2f7STomohiro Kusumi.Pp
42ce4dc2f7STomohiro KusumiAlternatively, to load the driver as a
43ce4dc2f7STomohiro Kusumimodule at boot time, place the following line in
44ce4dc2f7STomohiro Kusumi.Xr loader.conf 5 :
45ce4dc2f7STomohiro Kusumi.Bd -literal -offset indent
46ce4dc2f7STomohiro Kusumidm_target_delay_load="YES"
47ce4dc2f7STomohiro Kusumi.Ed
48ce4dc2f7STomohiro Kusumi.Sh DESCRIPTION
49ce4dc2f7STomohiro KusumiThe
50ce4dc2f7STomohiro Kusumi.Nm
51ce4dc2f7STomohiro Kusumitarget for
52ce4dc2f7STomohiro Kusumi.Xr dm 4
5388573254SSascha Wildnerprovides I/O delay for read or both read and write, and maps them to
5488573254SSascha Wildnerspecified devices, compatible with Linux dm-delay.
5588573254SSascha Wildner.Dq Nm dmsetup Cm create
5688573254SSascha Wildnertakes the following list of parameters for the
5788573254SSascha Wildner.Nm
58ce4dc2f7STomohiro Kusumitable.
59ce4dc2f7STomohiro Kusumi.Bd -ragged -offset indent
60ce4dc2f7STomohiro Kusumi.Cd "<read_device> <read_offset> <read_delay> [<write_device> <write_offset> <write_delay>]"
61ce4dc2f7STomohiro Kusumi.Ed
62ce4dc2f7STomohiro Kusumi.Pp
63ce4dc2f7STomohiro KusumiParameters for write delay are optional.
64037a33c5STomohiro KusumiIf write parameters are not specified, read parameters are used for write.
65037a33c5STomohiro KusumiIn order to only delay read, explicitly specify 0 delay for write.
66037a33c5STomohiro Kusumi.Pp
67ce4dc2f7STomohiro KusumiOffsets are specified in 512 bytes sectors.
68ce4dc2f7STomohiro KusumiDelays are specified in milliseconds.
69ce4dc2f7STomohiro Kusumi.Sh SEE ALSO
70ce4dc2f7STomohiro Kusumi.Xr dm 4 ,
71ce4dc2f7STomohiro Kusumi.Xr dmsetup 8
72ce4dc2f7STomohiro Kusumi.Sh HISTORY
73ce4dc2f7STomohiro KusumiThe
74ce4dc2f7STomohiro Kusumi.Nm
75ce4dc2f7STomohiro Kusumi.Xr dm 4
76ce4dc2f7STomohiro Kusumitarget first appeared in
77ce4dc2f7STomohiro Kusumi.Dx 4.3 .
78ce4dc2f7STomohiro Kusumi.Sh AUTHORS
79*b0a9540aSTomohiro Kusumi.An Tomohiro Kusumi Aq Mt tkusumi@netbsd.org
80