diff options
Diffstat (limited to 'static/freebsd/man4/syncer.4 3.html')
| -rw-r--r-- | static/freebsd/man4/syncer.4 3.html | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/static/freebsd/man4/syncer.4 3.html b/static/freebsd/man4/syncer.4 3.html new file mode 100644 index 00000000..36473d32 --- /dev/null +++ b/static/freebsd/man4/syncer.4 3.html @@ -0,0 +1,86 @@ +<table class="head"> + <tr> + <td class="head-ltitle">SYNCER(4)</td> + <td class="head-vol">Device Drivers Manual</td> + <td class="head-rtitle">SYNCER(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">syncer</code> — <span class="Nd">file + system synchronizer kernel process</span></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1> +<table class="Nm"> + <tr> + <td><code class="Nm">syncer</code></td> + <td></td> + </tr> +</table> +</section> +<section class="Sh"> +<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1> +<p class="Pp">The <code class="Nm">syncer</code> kernel process helps protect + the integrity of disk volumes by flushing volatile cached file system data + to disk.</p> +<p class="Pp">The kernel places all <a class="Xr">vnode(9)</a>'s in a number of + queues. The <code class="Nm">syncer</code> process works through the queues + in a round-robin fashion, usually processing one queue per second. For each + <a class="Xr">vnode(9)</a> on that queue, the <code class="Nm">syncer</code> + process forces a write out to disk of its dirty buffers.</p> +<p class="Pp">The usual delay between the time buffers are dirtied and the time + they are synced is controlled by the following <a class="Xr">sysctl(8)</a> + tunable variables:</p> +<table class="Bl-column"> + <tr id="Variable"> + <td><a class="permalink" href="#Variable"><i class="Em">Variable</i></a></td> + <td><a class="permalink" href="#Default"><i class="Em" id="Default">Default</i></a></td> + <td><a class="permalink" href="#Description"><i class="Em" id="Description">Description</i></a></td> + </tr> + <tr id="kern.filedelay"> + <td><var class="Va">kern.filedelay</var></td> + <td>30</td> + <td>time to delay syncing files</td> + </tr> + <tr id="kern.dirdelay"> + <td><var class="Va">kern.dirdelay</var></td> + <td>29</td> + <td>time to delay syncing directories</td> + </tr> + <tr id="kern.metadelay"> + <td><var class="Va">kern.metadelay</var></td> + <td>28</td> + <td>time to delay syncing metadata</td> + </tr> +</table> +</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">sync(2)</a>, <a class="Xr">fsck(8)</a>, + <a class="Xr">sync(8)</a>, <a class="Xr">sysctl(8)</a></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1> +<p class="Pp">The <code class="Nm">syncer</code> process is a descendant of the + ‘update’ command, which appeared in + <span class="Ux">Version 6 AT&T UNIX</span>, and was usually + started by <span class="Pa">/etc/rc</span> when the system went multi-user. + A kernel initiated ‘update’ process first appeared in + <span class="Ux">FreeBSD 2.0</span>.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="BUGS"><a class="permalink" href="#BUGS">BUGS</a></h1> +<p class="Pp">It is possible on some systems that a <a class="Xr">sync(2)</a> + occurring simultaneously with a crash may cause file system damage. See + <a class="Xr">fsck(8)</a>.</p> +</section> +</div> +<table class="foot"> + <tr> + <td class="foot-date">July 14, 2000</td> + <td class="foot-os">FreeBSD 15.0</td> + </tr> +</table> |