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.Nm ufs 40.Nd Berkeley fast file system 41.Sh SYNOPSIS 42In the kernel configuration file: 43.Cd "options FFS" 44.Cd "options QUOTA" 45.Cd "options SOFTUPDATES" 46.Cd "options SUIDDIR" 47.Cd "options UFS_DIRHASH" 48.Pp 49In 50.Xr fstab 5 : 51.Bd -literal -compact 52/dev/disk0a /mnt ufs rw 1 1 53.Ed 54.Sh DESCRIPTION 55The Berkeley fast file system 56provides facilities to store file system data onto a disk device. 57.Nm 58has been optimized over the years 59for speed and reliability 60and is the default 61.Dx 62file system. 63.Pp 64The following 65.Xr sysctl 8 66MIBs are defined for use with 67.Nm : 68.Bl -hang -width ".Va vfs.ffs.doreallocblk" 69.It Va vfs.ffs.doasyncfree 70Asynchronously write out modified i-node and indirect blocks 71upon reallocating file system blocks to be contiguous. 72(Default: 1.) 73.It Va vfs.ffs.doreallocblks 74Enable support for the rearrangement of blocks 75to be contiguous. 76(Default: 1.) 77.El 78.Ss Quotas 79.Bl -tag -width 2n 80.It Cd "options QUOTA" 81This option allows system administrators 82to set limits on disk usage 83on a per-user basis. 84Quotas can be used only on file systems 85mounted with the 86.Cm quota 87option; 88see 89.Xr quota 1 90and 91.Xr edquota 8 . 92.El 93.Ss Soft Updates 94.Bl -tag -width 2n 95.It Cd "options SOFTUPDATES" 96The soft updates feature tracks writes to the disk 97and enforces metadata update dependencies 98(e.g., updating free block maps) 99to ensure that the file system remains consistent. 100.Pp 101To enable soft updates on an 102.Em unmounted 103file system, use the following command: 104.Pp 105.D1 Nm tunefs Fl n Cm enable Ar fs 106.Pp 107.Ar fs 108can be either a mount point listed in 109.Xr fstab 5 110(e.g., 111.Pa /usr ) , 112or a disk device 113(e.g., 114.Pa /dev/da0s0a ) . 115.El 116.Ss File Ownership Inheritance 117.Bl -tag -width 2n 118.It Cd "options SUIDDIR" 119For use in file sharing environments 120on networks including 121.Tn "Microsoft Windows" 122and 123.Tn "Apple Macintosh" 124computers, 125this option allows files on file systems 126mounted with the 127.Cm suiddir 128option 129to inherit the ownership of its directory, 130i.e., 131.Dq "if it's my directory, it must be my file." 132.El 133.Ss Directory Hashing 134.Bl -tag -width 2n 135.It Cd "options UFS_DIRHASH" 136Implements a hash-based lookup scheme for directories 137in order to speed up accesses to very large directories. 138.El 139.Sh SEE ALSO 140.Xr quota 1 , 141.Xr edquota 8 , 142.Xr sysctl 8 143.Rs 144.%A M. McKusick 145.%A W. Joy 146.%A S. Leffler 147.%A R. Fabry 148.%D August 1984 149.%T "A Fast File System for UNIX" 150.%J "ACM Transactions on Computer Systems" 151.%N 2 152.%V 3 153.%P 181-197 154.Re 155.Rs 156.%A M. McKusick 157.%D June 2000 158.%T "Soft Updates: A Technique for Eliminating Most Synchronous Writes in the Fast Filesystem" 159.%J "Proceedings of the Freenix Track at the 1999 Usenix Annual Technical Conference" 160.%P 71-84 161.Re 162