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SAVE-ENTROPY(8) FreeBSD System Manager's Manual SAVE-ENTROPY(8)
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
syslog(3), random(4), rc.conf(5), cron(8)
HISTORY
The save-entropy command first appeared in FreeBSD 5.0.
AUTHORS
The save-entropy command was originally written by Doug Barton
<dougb@FreeBSD.org>. This manual page was written by
Fernando Apesteguia <fernape@FreeBSD.org>.
FreeBSD 14.2-RELEASE September 18, 2023 FreeBSD 14.2-RELEASE