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

# NAME

`fsirand` —
install random inode generation numbers in a filesystem

# SYNOPSIS

`fsirand` | [`-F`] [`-p`] [`-x` constant] special

# DESCRIPTION

`fsirand` writes random inode generation numbers for all the inodes on device special. These random numbers make the NFS filehandles less predictable, which was once thought to increase security of exported file systems.

`fsirand` is no longer relevant because newfs(8) has randomized inode generation numbers on all new file systems since NetBSD 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.

`fsirand` should be run on a clean and unmounted filesystem.

The options are as follows:

`-F`
  Indicates that special is a file system image, rather than a device name. special will be accessed ‘as-is’, without requiring that it is a raw character device and without attempting to read a disklabel.
`-p`
  Print the current inode generation numbers; the filesystem is not modified.
`-x` constant
  Exclusive-or the given constant with the random number used in the generation process.

`fsirand` exits zero on success, non-zero on failure.

If `fsirand` receives a `SIGINFO` signal, statistics on the amount of work completed and estimated completion time (in minutes:seconds) will be written to the standard error output.

# SEE ALSO

fsck_ffs(8), newfs(8)

# HISTORY

A `fsirand` utility appeared in NetBSD 1.3.

# AUTHORS

Christos Zoulas <christos@NetBSD.org>.

September 11, 2016 | NetBSD 10.1