.\"	$NetBSD: fsirand.8,v 1.10.24.1 2024/08/24 16:19:29 martin Exp $
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Christos Zoulas.
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.Dd September 11, 2016
.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, which
was once thought to increase security of exported file systems.
.Pp
.Nm
is no longer relevant because
.Xr newfs 8
has randomized inode generation numbers on all new file systems since
.Nx 2.0 ,
and in any case, exporting a file system to NFS clients allows them to
traverse the entire file system, so making filehandles less predictable
does not prevent clients from finding them anyway.
.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 HISTORY
A
.Nm
utility appeared in
.Nx 1.3 .
.Sh AUTHORS
.An Christos Zoulas Aq Mt christos@NetBSD.org .