xref: /freebsd/sbin/fsirand/fsirand.8 (revision c43e99fd14c915adcb7173dd49c31e803ceadfe0)
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
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12.\" 3. All advertising materials mentioning features or use of this software
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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
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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