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FSIRAND(8)                BSD System Manager's Manual               FSIRAND(8)

     fsirand -- randomize inode generation numbers

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

     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.

     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.

     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.

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

     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.

     Todd C. Miller <Todd.MillerATcourtesan.com>

BSD                            January 25, 1997                            BSD