.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
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.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by Todd C. Miller.
.\" 4. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
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.\"	$OpenBSD: fsirand.8,v 1.6 1997/02/23 03:58:26 millert Exp $
.\"
.Dd January 25, 1997
.Dt FSIRAND 8
.Os
.Sh NAME
.Nm fsirand
.Nd randomize inode generation numbers
.Sh SYNOPSIS
.Nm fsirand
.Op Fl b
.Op Fl f
.Op Fl p
.Ar special
.Op Ar "special ..."
.Sh DESCRIPTION
The
.Nm fsirand
command installs random generation numbers on all the inodes for
each filesystem specified on the command line by
.Ar special .
This increases the security of NFS-exported filesystems by making
it difficult to ``guess'' filehandles.
.Pp
.Em Note:
.Xr newfs 8
now does the equivalent of
.Nm
itself so it is no longer necessary to
run
.Nm
by hand on a new filesystem.  It is only used to
re-randomize or report on an existing filesystem.
.Pp
.Nm Fsirand
should only be used on an unmounted filesystem that
has been checked with
.Xr fsck 8
or a filesystem that is mounted read-only.
.Nm Fsirand
may be used on the root filesystem in single-user mode
but the system should be rebooted via ``reboot -n'' afterwards.
.Sh OPTIONS
.Bl -tag -width indent
The available options are as follows:
.It Fl b
Use the default block size (usually 512 bytes) instead
of the value gleaned from the disklabel.
.It Fl f
Force
.Nm
to run even if the filesystem on
.Ar special
is not marked as clean.
.It Fl p
Print the current generation numbers for all inodes instead of
generating new ones.
.Sh CAVEATS
Since
.Nm
allocates enough memory to hold all the inodes in
a given cylinder group it is may use a large amount
of memory for large disks with few cylinder groups.
.Sh SEE ALSO
.Xr fs 5 ,
.Xr fsck 8 ,
.Xr newfs 8 .
.Sh HISTORY
The
.Nm
command appeared in SunOS 3.x.
.br
This version of
.Nm
first appeared in
.Ox 2.1 .
A
.Tn FreeBSD
version first appeared in
.Fx 2.2.5 .
.Sh AUTHOR
.nf
Todd C. Miller <Todd.Miller@courtesan.com>
.fi