NAME
save-entropy – Save bits of entropy to feed /dev/random at startup
SYNOPSIS
save-entropy
DESCRIPTION
The save-entropy command is used to save entropy data from /dev/random to files in a specified output location. The files saved are used at startup to provide additional entropy for /dev/random. The output file will be different in every invocation until the maximum number of different files is reached. (See entropy_save_num for details). By default this script is invoked via cron(8) every eleven minutes approximately.
This command does nothing if executed inside a jail(8).
Three variables in /etc/rc.conf regulate the behavior of the script:
- entropy_dir
-
Specify the directory for saved entropy files. Defaults to /var/db/entropy. If set to "NO" it disables caching entropy via cron(8). This setting is shared with /etc/rc.d/random.
- entropy_save_sz
-
Size of the entropy cache files. Defaults to 4096.
- entropy_save_num
-
Number of entropy cache files to save. Defaults to 8.
FILES
- /etc/rc.conf
EXIT STATUS
The save-entropy utility exits 0 on success, and >0 if an error occurs. Errors will be recorded in the system log.
SEE ALSO
HISTORY
The save-entropy command first appeared in FreeBSD 5.0.
AUTHORS
The save-entropy command was originally written by Doug Barton <[email protected]>. This manual page was written by Fernando Apesteguia <[email protected]>.