xref: /freebsd/sbin/fsirand/fsirand.8 (revision 2008043f386721d58158e37e0d7e50df8095942d)
1.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
2.\" All rights reserved.
3.\"
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5.\" modification, are permitted provided that the following conditions
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14.\"	This product includes software developed by Todd C. Miller.
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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