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Diffstat (limited to 'lib/geom/nop/gnop.8')
| -rw-r--r-- | lib/geom/nop/gnop.8 | 211 |
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diff --git a/lib/geom/nop/gnop.8 b/lib/geom/nop/gnop.8 new file mode 100644 index 000000000000..24293d143058 --- /dev/null +++ b/lib/geom/nop/gnop.8 @@ -0,0 +1,211 @@ +.\" Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org> +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.Dd December 29, 2019 +.Dt GNOP 8 +.Os +.Sh NAME +.Nm gnop +.Nd "control utility for NOP GEOM class" +.Sh SYNOPSIS +.Nm +.Cm create +.Op Fl v +.Op Fl c Ar count_until_fail +.Op Fl d Ar delaymsec +.Op Fl e Ar error +.Op Fl o Ar offset +.Op Fl p Ar stripesize +.Op Fl P Ar stripeoffset +.Op Fl q Ar rdelayprob +.Op Fl r Ar rfailprob +.Op Fl s Ar size +.Op Fl S Ar secsize +.Op Fl w Ar wfailprob +.Op Fl x Ar wdelayprob +.Op Fl z Ar physpath +.Op Fl Z Ar gnopname +.Ar dev ... +.Nm +.Cm configure +.Op Fl v +.Op Fl c Ar count_until_fail +.Op Fl d Ar delaymsec +.Op Fl e Ar error +.Op Fl q Ar rdelayprob +.Op Fl r Ar rfailprob +.Op Fl w Ar wfailprob +.Op Fl x Ar wdelayprob +.Ar prov ... +.Nm +.Cm destroy +.Op Fl fv +.Ar prov ... +.Nm +.Cm reset +.Op Fl v +.Ar prov ... +.Nm +.Cm list +.Nm +.Cm status +.Nm +.Cm load +.Nm +.Cm unload +.Sh DESCRIPTION +The +.Nm +utility is used for setting up transparent providers on existing ones. +Its main purpose is testing other GEOM classes, as it allows forced provider +removal and I/O error simulation with a given probability. +It also gathers statistics on the number of read, write, delete, +getattr, flush, and other requests, and the number of bytes read and written. +.Nm +can also be used as a good starting point for implementing new GEOM +classes. +.Pp +The first argument to +.Nm +indicates an action to be performed: +.Bl -tag -width ".Cm configure" +.It Cm create +Set up a transparent provider on the given devices. +If the operation succeeds, the new provider should appear with name +.Pa /dev/ Ns Ao Ar dev Ac Ns Pa .nop . +The kernel module +.Pa geom_nop.ko +will be loaded if it is not loaded already. +.It Cm configure +Configure existing transparent provider. +At the moment it is only used for changing failure probability. +.It Cm destroy +Turn off the given transparent providers. +.It Cm reset +Reset statistics for the given transparent providers. +.It Cm list +See +.Xr geom 8 . +.It Cm status +See +.Xr geom 8 . +.It Cm load +See +.Xr geom 8 . +.It Cm unload +See +.Xr geom 8 . +.El +.Pp +Additional options: +.Bl -tag -width "-c count_until_fail" +.It Fl c Ar count_until_fail +Specifies the number of I/O requests to allow before setting the read, write and +delay failure probabilities. +.It Fl d Ar delaymsec +Specifies the delay of the requests in milliseconds. +Note that requests will be delayed before they are sent to the backing device. +.It Fl e Ar error +Specifies the error number to return on failure. +.It Fl f +Force the removal of the specified provider. +.It Fl o Ar offset +Where to begin on the original provider. +.It Fl p Ar stripesize +Value of the stripesize property of the transparent provider. +.It Fl P Ar stripeoffset +Value of the stripeoffset property of the transparent provider. +.It Fl q Ar rdelayprob +Specifies read delay probability in percent. +.It Fl r Ar rfailprob +Specifies read failure probability in percent. +.It Fl s Ar size +Size of the transparent provider. +.It Fl S Ar secsize +Sector size of the transparent provider. +.It Fl w Ar wfailprob +Specifies write failure probability in percent. +.It Fl v +Be more verbose. +.It Fl x Ar wdelayprob +Specifies write delay probability in percent. +.It Fl z Ar physpath +Physical path of the transparent provider. +.It Fl Z Ar gnopname +The name of the new provider. +The suffix +.Dq .nop +will be appended to the provider name. +.El +.Sh SYSCTL VARIABLES +The following +.Xr sysctl 8 +variables can be used to control the behavior of the +.Nm NOP +GEOM class. +The default value is shown next to each variable. +.Bl -tag -width indent +.It Va kern.geom.nop.debug : No 0 +Debug level of the +.Nm NOP +GEOM class. +This can be set to a number between 0 and 2 inclusive. +If set to 0, minimal debug information is printed. +If set to 1, basic debug information is logged along with the I/O requests +that were returned as errors. +If set to 2, the maximum amount of debug information is printed including +all I/O requests. +.El +.Sh EXIT STATUS +Exit status is 0 on success, and 1 if the command fails. +.Sh EXAMPLES +The following example shows how to create a transparent provider for disk +.Pa /dev/da0 +with 50% write failure probability, and how to destroy it. +.Bd -literal -offset indent +gnop create -v -w 50 da0 +gnop destroy -v da0.nop +.Ed +.Pp +The traffic statistics for the given transparent providers can be obtained +with the +.Cm list +command. +The example below shows the number of bytes written with +.Xr newfs 8 : +.Bd -literal -offset indent +gnop create da0 +newfs /dev/da0.nop +gnop list +.Ed +.Sh SEE ALSO +.Xr geom 4 , +.Xr geom 8 +.Sh HISTORY +The +.Nm +utility appeared in +.Fx 5.3 . +.Sh AUTHORS +.An Pawel Jakub Dawidek Aq Mt pjd@FreeBSD.org |