Installation guide

# sync
# sync
# halt
In response to the halt command, the program logs the shutdown in the
log file, kills all running processes, executes the sync system call and waits
for all information to be written to disk, then halts the systems. Note that
entering the sync command at least twice ensures that all data in memory
is safely written to disk. Refer to the halt
(8) reference page for a
description of the command and its flags.
3–20 Starting Up and Shutting Down the System