+++ /dev/null
-<?xml version="1.0" encoding="iso-8859-1"?>
-<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
-<refentry id="vfs_aio_pthread.8">
-
-<refmeta>
- <refentrytitle>vfs_aio_pthread</refentrytitle>
- <manvolnum>8</manvolnum>
- <refmiscinfo class="source">Samba</refmiscinfo>
- <refmiscinfo class="manual">System Administration tools</refmiscinfo>
- <refmiscinfo class="version">3.6</refmiscinfo>
-</refmeta>
-
-
-<refnamediv>
- <refname>vfs_aio_pthread</refname>
- <refpurpose>implement async I/O in Samba vfs using a pthread pool</refpurpose>
-</refnamediv>
-
-<refsynopsisdiv>
- <cmdsynopsis>
- <command>vfs objects = aio_pthread</command>
- </cmdsynopsis>
-</refsynopsisdiv>
-
-<refsect1>
- <title>DESCRIPTION</title>
-
- <para>This VFS module is part of the
- <citerefentry><refentrytitle>samba</refentrytitle>
- <manvolnum>7</manvolnum></citerefentry> suite.</para>
-
- <para>The <command>aio_pthread</command> VFS module enables asynchronous
- I/O for Samba on platforms which have the pthreads API available,
- without using the Posix AIO interface. Posix AIO can suffer from severe
- limitations. For example, on some Linux versions the
- real-time signals that it uses are broken under heavy load.
- Other systems only allow AIO when special kernel modules are
- loaded or only allow a certain system-wide amount of async
- requests being scheduled. Systems based on glibc (most Linux
- systems) only allow a single outstanding request per file
- descriptor which essentially makes Posix AIO useless on systems
- using the glibc implementation.</para>
-
- <para>To work around all these limitations, the aio_pthread module
- was written. It uses a pthread pool instead of the
- internal Posix AIO interface to allow read and write calls
- to be process asynchronously. A pthread pool is created
- which expands dynamically by creating new threads as work is
- given to it to a maximum of 100 threads per smbd process.
- To change this limit see the "aio num threads" parameter
- below. New threads are not created if idle threads are
- available when a new read or write request is received,
- the new work is given to an existing idle thread. Threads
- terminate themselves if idle for one second.
- </para>
-
- <para>
- Note that the smb.conf parameters <command>aio read size</command>
- and <command>aio write size</command> must also be set appropriately
- for this module to be active.
- </para>
-
- <para>This module MUST be listed last in any module stack as
- the Samba VFS pread/pwrite interface is not thread-safe. This
- module makes direct pread and pwrite system calls and does
- NOT call the Samba VFS pread and pwrite interfaces.</para>
-
-</refsect1>
-
-
-<refsect1>
- <title>EXAMPLES</title>
-
- <para>Straight forward use:</para>
-
-<programlisting>
- <smbconfsection name="[cooldata]"/>
- <smbconfoption name="path">/data/ice</smbconfoption>
- <smbconfoption name="aio read size">1024</smbconfoption>
- <smbconfoption name="aio write size">1024</smbconfoption>
- <smbconfoption name="vfs objects">aio_pthread</smbconfoption>
-</programlisting>
-
-</refsect1>
-
-<refsect1>
- <title>OPTIONS</title>
-
- <variablelist>
-
- <varlistentry>
- <term>aio_pthread:aio num threads = INTEGER</term>
- <listitem>
- <para>Limit the maximum number of threads per smbd that
- will be created in the thread pool to service IO requests.
- </para>
- <para>By default this is set to 100.</para>
- </listitem>
- </varlistentry>
-
- </variablelist>
-</refsect1>
-<refsect1>
- <title>VERSION</title>
-
- <para>This man page is correct for version 3.6.3 of the Samba suite.
- </para>
-</refsect1>
-
-<refsect1>
- <title>AUTHOR</title>
-
- <para>The original Samba software and related utilities
- were created by Andrew Tridgell. Samba is now developed
- by the Samba Team as an Open Source project similar
- to the way the Linux kernel is developed.</para>
-
-</refsect1>
-
-</refentry>
git.samba.org / kai / samba.git / blobdiff