xref: /freebsd/sbin/fsirand/fsirand.8 (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\" 3. All advertising materials mentioning features or use of this software
13.\"    must display the following acknowledgment:
14.\"	This product includes software developed by Todd C. Miller.
15.\" 4. The name of the author may not be used to endorse or promote products
16.\"    derived from this software without specific prior written permission.
17.\"
18.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20.\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
21.\" THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22.\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23.\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24.\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27.\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28.\"
29.\"	$OpenBSD: fsirand.8,v 1.6 1997/02/23 03:58:26 millert Exp $
30.\" $FreeBSD$
31.\"
32.Dd January 25, 1997
33.Dt FSIRAND 8
34.Os
35.Sh NAME
36.Nm fsirand
37.Nd randomize inode generation numbers
38.Sh SYNOPSIS
39.Nm
40.Op Fl b
41.Op Fl f
42.Op Fl p
43.Ar special
44.Op Ar "special ..."
45.Sh DESCRIPTION
46The
47.Nm
48utility installs random generation numbers on all the inodes for
49each file system specified on the command line by
50.Ar special .
51This increases the security of NFS-exported file systems by making
52it difficult to ``guess'' filehandles.
53.Pp
54.Em Note :
55.Xr newfs 8
56now does the equivalent of
57.Nm
58itself so it is no longer necessary to
59run
60.Nm
61by hand on a new file system.
62It is only used to
63re-randomize or report on an existing file system.
64.Pp
65The
66.Nm
67utility should only be used on an unmounted file system that
68has been checked with
69.Xr fsck 8
70or a file system that is mounted read-only.
71The
72.Nm
73utility may be used on the root file system in single-user mode
74but the system should be rebooted via ``reboot -n'' afterwards.
75.Sh OPTIONS
76The available options are as follows:
77.Bl -tag -width indent
78.It Fl b
79Use the default block size (usually 512 bytes) instead
80of the value gleaned from the disklabel.
81.It Fl f
82Force
83.Nm
84to run even if the file system on
85.Ar special
86is not marked as clean.
87.It Fl p
88Print the current generation numbers for all inodes instead of
89generating new ones.
90.El
91.Sh SEE ALSO
92.Xr fs 5 ,
93.Xr fsck 8 ,
94.Xr newfs 8
95.Sh HISTORY
96The
97.Nm
98utility appeared in SunOS 3.x.
99.Pp
100This version of
101.Nm
102first appeared in
103.Ox 2.1 .
104.Pp
105A
106.Fx
107version first appeared in
108.Fx 2.2.5 .
109.Sh AUTHORS
110.An Todd C. Miller Aq Mt Todd.Miller@courtesan.com
111.Sh CAVEATS
112Since
113.Nm
114allocates enough memory to hold all the inodes in
115a given cylinder group it may use a large amount
116of memory for large disks with few cylinder groups.
117