1.\" Copyright (c) 2001 Networks Associates Technology, Inc. 2.\" All rights reserved. 3.\" 4.\" This software was developed for the FreeBSD Project by Chris 5.\" Costello at Safeport Network Services and NAI Labs, the Security 6.\" Research Division of Network Associates, Inc. under DARPA/SPAWAR 7.\" contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS 8.\" research program. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" $FreeBSD: src/share/man/man7/ffs.7,v 1.13 2005/07/23 15:09:27 markus Exp $ 32.\" $DragonFly: src/share/man/man5/ffs.5,v 1.2 2008/07/27 22:21:11 thomas Exp $ 33.\" 34.Dd May 10, 2008 35.Dt FFS 5 36.Os 37.Sh NAME 38.Nm ffs 39.Nd Berkeley fast file system 40.Sh SYNOPSIS 41In the kernel configuration file: 42.Cd "options FFS" 43.Cd "options QUOTA" 44.Cd "options SOFTUPDATES" 45.Cd "options SUIDDIR" 46.Cd "options UFS_DIRHASH" 47.Pp 48In 49.Xr fstab 5 : 50.Bd -literal -compact 51/dev/disk0a /mnt ufs rw 1 1 52.Ed 53.Sh DESCRIPTION 54The Berkeley fast file system 55provides facilities to store file system data onto a disk device. 56.Nm 57has been optimized over the years 58for speed and reliability 59and is the default 60.Dx 61file system. 62.Pp 63The following 64.Xr sysctl 8 65MIBs are defined for use with 66.Nm : 67.Bl -hang -width ".Va vfs.ffs.doreallocblk" 68.It Va vfs.ffs.doasyncfree 69Asynchronously write out modified i-node and indirect blocks 70upon reallocating file system blocks to be contiguous. 71(Default: 1.) 72.It Va vfs.ffs.doreallocblks 73Enable support for the rearrangement of blocks 74to be contiguous. 75(Default: 1.) 76.El 77.Ss Quotas 78.Bl -tag -width 2n 79.It Cd "options QUOTA" 80This option allows system administrators 81to set limits on disk usage 82on a per-user basis. 83Quotas can be used only on file systems 84mounted with the 85.Cm quota 86option; 87see 88.Xr quota 1 89and 90.Xr edquota 8 . 91.El 92.Ss Soft Updates 93.Bl -tag -width 2n 94.It Cd "options SOFTUPDATES" 95The soft updates feature tracks writes to the disk 96and enforces metadata update dependencies 97(e.g., updating free block maps) 98to ensure that the file system remains consistent. 99.Pp 100To enable soft updates on an 101.Em unmounted 102file system, use the following command: 103.Pp 104.D1 Nm tunefs Fl n Cm enable Ar fs 105.Pp 106.Ar fs 107can be either a mount point listed in 108.Xr fstab 5 109(e.g., 110.Pa /usr ) , 111or a disk device 112(e.g., 113.Pa /dev/da0s0a ) . 114.El 115.Ss File Ownership Inheritance 116.Bl -tag -width 2n 117.It Cd "options SUIDDIR" 118For use in file sharing environments 119on networks including 120.Tn "Microsoft Windows" 121and 122.Tn "Apple Macintosh" 123computers, 124this option allows files on file systems 125mounted with the 126.Cm suiddir 127option 128to inherit the ownership of its directory, 129i.e., 130.Dq "if it's my directory, it must be my file." 131.El 132.Ss Directory Hashing 133.Bl -tag -width 2n 134.It Cd "options UFS_DIRHASH" 135Implements a hash-based lookup scheme for directories 136in order to speed up accesses to very large directories. 137.El 138.Sh SEE ALSO 139.Xr quota 1 , 140.Xr edquota 8 , 141.Xr sysctl 8 142.Rs 143.%A M. McKusick 144.%A W. Joy 145.%A S. Leffler 146.%A R. Fabry 147.%D August 1984 148.%T "A Fast File System for UNIX" 149.%J "ACM Transactions on Computer Systems" 150.%N 2 151.%V 3 152.%P 181-197 153.Re 154.Rs 155.%A M. McKusick 156.%D June 2000 157.%T "Soft Updates: A Technique for Eliminating Most Synchronous Writes in the Fast Filesystem" 158.%J "Proceedings of the Freenix Track at the 1999 Usenix Annual Technical Conference" 159.%P 71-84 160.Re 161