xref: /freebsd/sbin/fsirand/fsirand.8 (revision fe75646a0234a261c0013bf1840fdac4acaf0cec)
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.\"
31.Dd January 25, 1997
32.Dt FSIRAND 8
33.Os
34.Sh NAME
35.Nm fsirand
36.Nd randomize inode generation numbers
37.Sh SYNOPSIS
38.Nm
39.Op Fl b
40.Op Fl f
41.Op Fl p
42.Ar special
43.Op Ar "special ..."
44.Sh DESCRIPTION
45The
46.Nm
47utility installs random generation numbers on all the inodes for
48each file system specified on the command line by
49.Ar special .
50This increases the security of NFS-exported file systems by making
51it difficult to ``guess'' filehandles.
52.Pp
53.Em Note :
54.Xr newfs 8
55now does the equivalent of
56.Nm
57itself so it is no longer necessary to
58run
59.Nm
60by hand on a new file system.
61It is only used to
62re-randomize or report on an existing file system.
63.Pp
64The
65.Nm
66utility should only be used on an unmounted file system that
67has been checked with
68.Xr fsck 8
69or a file system that is mounted read-only.
70The
71.Nm
72utility may be used on the root file system in single-user mode
73but the system should be rebooted via ``reboot -n'' afterwards.
74.Sh OPTIONS
75The available options are as follows:
76.Bl -tag -width indent
77.It Fl b
78Use the default block size (usually 512 bytes) instead
79of the value gleaned from the disklabel.
80.It Fl f
81Force
82.Nm
83to run even if the file system on
84.Ar special
85is not marked as clean.
86.It Fl p
87Print the current generation numbers for all inodes instead of
88generating new ones.
89.El
90.Sh SEE ALSO
91.Xr fs 5 ,
92.Xr fsck 8 ,
93.Xr newfs 8
94.Sh HISTORY
95The
96.Nm
97utility appeared in SunOS 3.x.
98.Pp
99This version of
100.Nm
101first appeared in
102.Ox 2.1 .
103.Pp
104A
105.Fx
106version first appeared in
107.Fx 2.2.5 .
108.Sh AUTHORS
109.An Todd C. Miller Aq Mt Todd.Miller@courtesan.com
110.Sh CAVEATS
111Since
112.Nm
113allocates enough memory to hold all the inodes in
114a given cylinder group it may use a large amount
115of memory for large disks with few cylinder groups.
116