NetBSD/sbin/fsirand/fsirand.8

.\"	$NetBSD: fsirand.8,v 1.7 2001/11/16 04:25:43 lukem Exp $
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Christos Zoulas.
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.Dd November 16, 2001
.Dt FSIRAND 8
.Os
.Sh NAME
.Nm fsirand
.Nd install random inode generation numbers in a filesystem
.Sh SYNOPSIS
.Nm
.Op Fl F
.Op Fl p
.Op Fl x Ar constant
.Ar special
.Sh DESCRIPTION
.Nm
writes random inode generation numbers for all the inodes on device
.Ar special .
These random numbers make the NFS filehandles less predictable, increasing
security of exported filesystems.
.Pp
.Nm
should be run on a clean and unmounted filesystem.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl F
Indicates that
.Ar special
is a file system image, rather than a device name.
.Ar special
will be accessed
.Sq as-is ,
without requiring that it is a raw character device and without
attempting to read a disklabel.
.It Fl p
Print the current inode generation numbers; the filesystem is not modified.
.It Fl x Ar constant
Exclusive-or the given constant with the random number used in the generation
process.
.El
.Pp
.Nm
exits zero on success, non-zero on failure.
.Pp
If
.Nm
receives a
.Dv SIGINFO
signal, statistics on the amount of work completed and estimated
completion time (in minutes:seconds) will be written to the standard
error output.
.Sh SEE ALSO
.Xr fsck_ffs 8 ,
.Xr newfs 8
.Sh SECURITY CONSIDERATIONS
The current implementation does not use a good random number generator,
so the randomization can be predicted.