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.\" 33.Dd February 17, 2018 34.Dt FFS 5 35.Os 36.Sh NAME 37.Nm ffs , 38.Nm ufs 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 for 62.Pa /boot . 63.Ss Quotas 64.Bl -tag -width 2n 65.It Cd "options QUOTA" 66This option allows system administrators 67to set limits on disk usage 68on a per-user basis. 69Quotas can be used only on file systems 70mounted with the 71.Cm quota 72option; 73see 74.Xr quota 1 75and 76.Xr edquota 8 . 77.El 78.Ss Soft Updates 79.Bl -tag -width 2n 80.It Cd "options SOFTUPDATES" 81The soft updates feature tracks writes to the disk 82and enforces metadata update dependencies 83(e.g., updating free block maps) 84to ensure that the file system remains consistent. 85.Pp 86To enable soft updates on an 87.Em unmounted 88file system, use the following command: 89.Pp 90.D1 Nm tunefs Fl n Cm enable Ar fs 91.Pp 92.Ar fs 93can be either a mount point listed in 94.Xr fstab 5 95(e.g., 96.Pa /usr ) , 97or a disk device 98(e.g., 99.Pa /dev/da0s0a ) . 100.El 101.Ss File Ownership Inheritance 102.Bl -tag -width 2n 103.It Cd "options SUIDDIR" 104For use in file sharing environments 105on networks including 106.Tn "Microsoft Windows" 107and 108.Tn "Apple Macintosh" 109computers, 110this option allows files on file systems 111mounted with the 112.Cm suiddir 113option 114to inherit the ownership of its directory, 115i.e., 116.Dq "if it's my directory, it must be my file." 117.El 118.Ss Directory Hashing 119.Bl -tag -width 2n 120.It Cd "options UFS_DIRHASH" 121Implements a hash-based lookup scheme for directories 122in order to speed up accesses to very large directories. 123.El 124.Sh SYSCTL VARIABLES 125The following 126.Xr sysctl 8 127MIBs are defined for use with 128.Nm : 129.Bl -hang -width ".Va vfs.ufs.dirhash_docheck" 130.It Va vfs.ffs.doasyncfree 131Asynchronously write out modified i-node and indirect blocks 132upon reallocating file system blocks to be contiguous. 133(Default: 1.) 134.It Va vfs.ffs.doreallocblks 135Enable support for the rearrangement of blocks 136to be contiguous. 137(Default: 1.) 138.It Va vfs.ufs.dirhash_docheck 139Enable extra sanity tests. 140(Default: 0.) 141.It Va vfs.ufs.dirhash_mem 142Current dirhash memory usage. 143.It Va vfs.ufs.dirhash_maxmem 144Maximum allowed dirhash memory usage. 145.It Va vfs.ufs.dirhash_minsize 146Minimum directory size in bytes for which to use hashed lookup. 147.El 148.Sh SEE ALSO 149.Xr quota 1 , 150.Xr edquota 8 , 151.Xr sysctl 8 152.Rs 153.%A M. McKusick 154.%A W. Joy 155.%A S. Leffler 156.%A R. Fabry 157.%D August 1984 158.%T "A Fast File System for UNIX" 159.%J "ACM Transactions on Computer Systems" 160.%N 2 161.%V 3 162.%P 181-197 163.Re 164.Rs 165.%A M. McKusick 166.%D June 2000 167.%T "Soft Updates: A Technique for Eliminating Most Synchronous Writes in the Fast Filesystem" 168.%J "Proceedings of the Freenix Track at the 1999 Usenix Annual Technical Conference" 169.%P 71-84 170.Re 171