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fsirand(8)

NAME

     fsirand -- randomize inode generation numbers

SYNOPSIS

     fsirand [-b] [-f] [-p] special [special ...]

DESCRIPTION

     The fsirand utility installs random generation numbers on all the inodes
     for each file system specified on the command line by special.  This
     increases the security of NFS-exported file systems by making it diffi-
     cult to ``guess'' filehandles.

     Note: newfs(8) now does the equivalent of fsirand itself so it is no
     longer necessary to run fsirand by hand on a new file system.  It is only
     used to re-randomize or report on an existing file system.

     The fsirand utility should only be used on an unmounted file system that
     has been checked with fsck(8) or a file system that is mounted read-only.
     The fsirand utility may be used on the root file system in single-user
     mode but the system should be rebooted via ``reboot -n'' afterwards.

OPTIONS

     The available options are as follows:

     -b      Use the default block size (usually 512 bytes) instead of the
	     value gleaned from the disklabel.

     -f      Force fsirand to run even if the file system on special is not
	     marked as clean.

     -p      Print the current generation numbers for all inodes instead of
	     generating new ones.

CAVEATS

     Since fsirand allocates enough memory to hold all the inodes in a given
     cylinder group it may use a large amount of memory for large disks with
     few cylinder groups.

SEE ALSO

     fs(5), fsck(8), newfs(8)

HISTORY

     The fsirand utility appeared in SunOS 3.x.

     This version of fsirand first appeared in OpenBSD 2.1.

     A FreeBSD version first appeared in FreeBSD 2.2.5.

AUTHORS

     Todd C. Miller <Todd.Miller@courtesan.com>

FreeBSD 5.4		       January 25, 1997 		   FreeBSD 5.4

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