1.\" $NetBSD: fsirand.8,v 1.7 2001/11/16 04:25:43 lukem Exp $ 2.\" 3.\" Copyright (c) 1997 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Christos Zoulas. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.Dd November 16, 2001 38.Dt FSIRAND 8 39.Os 40.Sh NAME 41.Nm fsirand 42.Nd install random inode generation numbers in a filesystem 43.Sh SYNOPSIS 44.Nm 45.Op Fl F 46.Op Fl p 47.Op Fl x Ar constant 48.Ar special 49.Sh DESCRIPTION 50.Nm 51writes random inode generation numbers for all the inodes on device 52.Ar special . 53These random numbers make the NFS filehandles less predictable, increasing 54security of exported filesystems. 55.Pp 56.Nm 57should be run on a clean and unmounted filesystem. 58.Pp 59The options are as follows: 60.Bl -tag -width indent 61.It Fl F 62Indicates that 63.Ar special 64is a file system image, rather than a device name. 65.Ar special 66will be accessed 67.Sq as-is , 68without requiring that it is a raw character device and without 69attempting to read a disklabel. 70.It Fl p 71Print the current inode generation numbers; the filesystem is not modified. 72.It Fl x Ar constant 73Exclusive-or the given constant with the random number used in the generation 74process. 75.El 76.Pp 77.Nm 78exits zero on success, non-zero on failure. 79.Pp 80If 81.Nm 82receives a 83.Dv SIGINFO 84signal, statistics on the amount of work completed and estimated 85completion time (in minutes:seconds) will be written to the standard 86error output. 87.Sh SEE ALSO 88.Xr fsck_ffs 8 , 89.Xr newfs 8 90.Sh SECURITY CONSIDERATIONS 91The current implementation does not use a good random number generator, 92so the randomization can be predicted. 93