'\" t .\" Title: vfs_aio_fork .\" Author: [see the "AUTHOR" section] .\" Generator: DocBook XSL Stylesheets vsnapshot .\" Date: 09/04/2024 .\" Manual: System Administration tools .\" Source: Samba 4.21.0 .\" Language: English .\" .TH "VFS_AIO_FORK" "8" "09/04/2024" "Samba 4\&.21\&.0" "System Administration tools" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" vfs_aio_fork \- implement async I/O in Samba vfs .SH "SYNOPSIS" .HP \w'\ 'u vfs objects = aio_fork .SH "DESCRIPTION" .PP This VFS module is part of the \fBsamba\fR(7) suite\&. .PP The aio_fork VFS module enables async I/O for Samba on platforms where the system level Posix AIO interface is insufficient\&. 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\&. .PP To work around all these limitations, the aio_fork module was written\&. It uses forked helper processes instead of the internal Posix AIO interface to create asynchronousity for read and write calls\&. It has no parameters, it will create helper processes when async requests come in as needed\&. Idle helper processes will be removed every 30 seconds\&. .PP This module is stackable\&. .SH "EXAMPLES" .PP Straight forward use: .sp .if n \{\ .RS 4 .\} .nf \fI[cooldata]\fR \m[blue]\fBpath = /data/ice\fR\m[] \m[blue]\fBvfs objects = aio_fork\fR\m[] .fi .if n \{\ .RE .\} .SH "VERSION" .PP This man page is part of version 4\&.21\&.0 of the Samba suite\&. .SH "AUTHOR" .PP 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\&.