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diff --git a/static/freebsd/man4/geom_zero.4 3.html b/static/freebsd/man4/geom_zero.4 3.html deleted file mode 100644 index bcb10b27..00000000 --- a/static/freebsd/man4/geom_zero.4 3.html +++ /dev/null @@ -1,144 +0,0 @@ -<table class="head"> - <tr> - <td class="head-ltitle">GEOM_ZERO(4)</td> - <td class="head-vol">Device Drivers Manual</td> - <td class="head-rtitle">GEOM_ZERO(4)</td> - </tr> -</table> -<div class="manual-text"> -<section class="Sh"> -<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1> -<p class="Pp"><code class="Nm">gzero</code>, <code class="Nm">geom_zero</code> - — <span class="Nd">GEOM-based zero disk/block device</span></p> -</section> -<section class="Sh"> -<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1> -<p class="Pp"><code class="Cd">options GEOM_ZERO</code></p> -<p class="Pp">In <a class="Xr">loader.conf(5)</a> or - <a class="Xr">sysctl.conf(5)</a>: - <br/> - <code class="Cd">kern.geom.zero.byte</code> - <br/> - <code class="Cd">kern.geom.zero.clear</code></p> -</section> -<section class="Sh"> -<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1> -<p class="Pp"><code class="Nm">gzero</code> is a <a class="Xr">GEOM(4)</a> - device simulating a one-exabyte disk. It throws away any data written to it, - and returns the value of <var class="Va">kern.geom.zero.byte</var> for every - byte read from it.</p> -<p class="Pp"><code class="Nm">gzero</code> differs from - <a class="Xr">zero(4)</a>, which is a regular character device and has an - infinite length, while <span class="Pa">/dev/gzero</span> is a - <a class="Xr">GEOM(4)</a> provider of large, but limited, size.</p> -<p class="Pp">Consult <a class="Xr">geom(8)</a> for instructions on how to use - the supported commands of the <a class="Xr">GEOM(4)</a> - <code class="Nm">ZERO</code> class.</p> -<p class="Pp"><code class="Nm">gzero</code> is useful for benchmarking - performance of GEOM and GEOM classes where compression of the data does not - affect the results (blocks from <span class="Pa">/dev/gzero</span> compress - exceptionally well). Examples of such benchmarks include comparing the speed - of two disk encryption algorithms and comparing a hardware versus software - implementation of a single encryption algorithm.</p> -</section> -<section class="Sh"> -<h1 class="Sh" id="MIB_VARIABLES"><a class="permalink" href="#MIB_VARIABLES">MIB - VARIABLES</a></h1> -<p class="Pp">The following variables are available as both - <a class="Xr">sysctl(8)</a> variables and <a class="Xr">loader(8)</a> - tunables:</p> -<dl class="Bl-tag"> - <dt id="kern.geom.zero.byte"><var class="Va">kern.geom.zero.byte</var></dt> - <dd>This variable sets the fill byte of the <code class="Nm">gzero</code> - device. Default: ‘<code class="Li">0</code>’.</dd> - <dt id="kern.geom.zero.clear"><var class="Va">kern.geom.zero.clear</var></dt> - <dd>This variable controls the clearing of the read data buffer. If set to - ‘<code class="Li">0</code>’, <code class="Nm">gzero</code> - will not copy any data into the read data buffers and just return the read - data buffers as they are without modifying them. In particular, it will - not fill the read buffer with the value of - <var class="Va">kern.geom.zero.byte</var>. This is useful for read - benchmarking to reduce the measurement noise caused by extra memory - initialization. Default: ‘<code class="Li">1</code>’.</dd> -</dl> -</section> -<section class="Sh"> -<h1 class="Sh" id="FILES"><a class="permalink" href="#FILES">FILES</a></h1> -<dl class="Bl-tag"> - <dt><span class="Pa">/dev/gzero</span></dt> - <dd>The <code class="Nm">gzero</code> device.</dd> -</dl> -</section> -<section class="Sh"> -<h1 class="Sh" id="EXAMPLES"><a class="permalink" href="#EXAMPLES">EXAMPLES</a></h1> -<p class="Pp">Create the <span class="Pa">/dev/gzero</span> device by loading - the <code class="Nm">geom_zero</code> kernel module:</p> -<div class="Bd Pp Bd-indent Li"> -<pre># geom zero load</pre> -</div> -<p class="Pp">Show information about the <code class="Nm">gzero</code> - device:</p> -<div class="Bd Pp Bd-indent Li"> -<pre># geom zero list -Geom name: gzero -Providers: -1. Name: gzero - Mediasize: 1152921504606846976 (1.0E) - Sectorsize: 512 - Mode: r0w0egzero0</pre> -</div> -<p class="Pp">Set the fill byte of the <code class="Nm">gzero</code> device to - 70 (decimal for letter “F” in <a class="Xr">ascii(7)</a>):</p> -<div class="Bd Pp Bd-indent Li"> -<pre># sysctl kern.geom.zero.byte=70 -kern.geom.zero.byte: 0 -> 70 -# head -c 1 /dev/gzero -F</pre> -</div> -<p class="Pp">Benchmark read and write throughput of <a class="Xr">geli(8)</a>'s - default encryption algorithm with a 4-KiB sector size:</p> -<div class="Bd Pp Bd-indent Li"> -<pre># geom zero load -# geli onetime -s 4096 gzero -# sysctl kern.geom.zero.clear=0 -# dd if=/dev/gzero.eli of=/dev/zero bs=4k count=$((1024 * 256)) -262144+0 records in -262144+0 records out -1073741824 bytes transferred in 1.258195 secs (853398307 bytes/sec) -# dd if=/dev/zero of=/dev/gzero.eli bs=4k count=$((1024 * 256)) -262144+0 records in -262144+0 records out -1073741824 bytes transferred in 1.663118 secs (645619658 bytes/sec)</pre> -</div> -</section> -<section class="Sh"> -<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE - ALSO</a></h1> -<p class="Pp"><a class="Xr">GEOM(4)</a>, <a class="Xr">zero(4)</a>, - <a class="Xr">geom(8)</a>, <a class="Xr">sysctl(8)</a>, - <a class="Xr">bio(9)</a></p> -</section> -<section class="Sh"> -<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1> -<p class="Pp">A <code class="Nm">gzero</code> device first appeared in - <span class="Ux">FreeBSD 6</span>.</p> -</section> -<section class="Sh"> -<h1 class="Sh" id="AUTHORS"><a class="permalink" href="#AUTHORS">AUTHORS</a></h1> -<p class="Pp">The <code class="Nm">gzero</code> device was written by - <span class="An">Paweł Jakub Dawidek</span> - <<a class="Mt" href="mailto:pjd@FreeBSD.org">pjd@FreeBSD.org</a>>.</p> -<p class="Pp">The <code class="Nm">gzero</code> manual page was originally - written by <span class="An">Greg White</span> - <<a class="Mt" href="mailto:gkwhite@gmail.com">gkwhite@gmail.com</a>> - and rewritten by <span class="An">Mateusz Piotrowski</span> - <<a class="Mt" href="mailto:0mp@FreeBSD.org">0mp@FreeBSD.org</a>> - before landing in <span class="Ux">FreeBSD</span>.</p> -</section> -</div> -<table class="foot"> - <tr> - <td class="foot-date">November 9, 2025</td> - <td class="foot-os">FreeBSD 15.0</td> - </tr> -</table> |