This is probably a dumb question with an easy answer, but I can't seem to shed any light on it after hours of Google-ing. From what I have learned the
halt command on UNIX (e.g BSD) & Unix-like Systems (e.g Linux) will halt the CPU after calling
sync. I know that on most modern Linux Distros
halt is just another way to call
shutdown, but I have installed FreeBSD and Arch Linux on my Laptop, and both of those systems seem to do what
halt is supposed to do (halt the CPU, but don't ACPI shutdown). My question is that after calling
# sync;sync;sync # halt
is it safe to "pull the plug" or cut the power (from the power socket at the wall)? After calling
halt is the system truly in an "off" state?
After calling halt on eiter Arch Linux or FreeBSD, my computer seems "halted", like it is unresponsive, and nothing works but I can still hear the fan running. The fan stops after I take the power out. So it's not a problem, I'm just wondering if maybe
halt doesn't stop all the hardware, and only stops the CPU?