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32 .Nd "control utility for NOP GEOM class"
39 .Op Fl p Ar stripesize
40 .Op Fl P Ar stripeoffset
73 utility is used for setting up transparent providers on existing ones.
74 Its main purpose is testing other GEOM classes, as it allows forced provider
75 removal and I/O error simulation with a given probability.
76 It also gathers statistics on the number of read, write, delete,
77 getattr, flush, and other requests, and the number of bytes read and written.
79 can also be used as a good starting point for implementing new GEOM
84 indicates an action to be performed:
85 .Bl -tag -width ".Cm configure"
87 Set up a transparent provider on the given devices.
88 If the operation succeeds, the new provider should appear with name
89 .Pa /dev/ Ns Ao Ar dev Ac Ns Pa .nop .
92 will be loaded if it is not loaded already.
94 Configure existing transparent provider.
95 At the moment it is only used for changing failure probability.
97 Turn off the given transparent providers.
99 Reset statistics for the given transparent providers.
115 .Bl -tag -width ".Fl r Ar rfailprob"
117 Specifies the error number to return on failure.
119 Force the removal of the specified provider.
121 Where to begin on the original provider.
122 .It Fl p Ar stripesize
123 Value of the stripesize property of the transparent provider.
124 .It Fl P Ar stripeoffset
125 Value of the stripeoffset property of the transparent provider.
126 .It Fl r Ar rfailprob
127 Specifies read failure probability in percent.
129 Size of the transparent provider.
131 Sector size of the transparent provider.
132 .It Fl w Ar wfailprob
133 Specifies write failure probability in percent.
137 Physical path of the transparent provider.
142 variables can be used to control the behavior of the
145 The default value is shown next to each variable.
146 .Bl -tag -width indent
147 .It Va kern.geom.nop.debug : No 0
151 This can be set to a number between 0 and 2 inclusive.
152 If set to 0, minimal debug information is printed.
153 If set to 1, basic debug information is logged along with the I/O requests
154 that were returned as errors.
155 If set to 2, the maximum amount of debug information is printed including
159 Exit status is 0 on success, and 1 if the command fails.
161 The following example shows how to create a transparent provider for disk
163 with 50% write failure probability, and how to destroy it.
164 .Bd -literal -offset indent
165 gnop create -v -w 50 da0
166 gnop destroy -v da0.nop
169 The traffic statistics for the given transparent providers can be obtained
173 The example below shows the number of bytes written with
175 .Bd -literal -offset indent
189 .An Pawel Jakub Dawidek Aq Mt pjd@FreeBSD.org