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 mak - ing it difficult 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 sys - tem. 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'' af - terwards.
OPTIONS
The available options are as follows:
- -b Use the default block size (usually 512 bytes) in
- stead 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
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>
- BSD January 25, 1997