[CentOS] halt versus shutdown

Working with different Linux Distributions makes the life harder.
So far I have found out that 'poweroff' & 'reboot' has the same behaviour on  Linux/Unix/BSDs.

Best Regards,
Strahil Nikolov

На 15 юни 2020 г. 5:22:28 GMT+03:00, John Pierce <jhn.pierce at gmail.com> написа:
>On Sun, Jun 14, 2020 at 6:19 PM Pete Biggs <pete at biggs.org.uk> wrote:
>
>>
>> > I'm quite sure that in original Berkeley Unix, as on the VAX
>11/780, halt
>> > was an immediate halt of the CPU without any process cleanup or
>file
>> system
>> > umounting or anything.   Early SunOS (pre-Solaris) was like this,
>too.
>> >
>> The SunOS 4.1.2 man page for halt says
>>
>>    NAME
>>       halt - stop the processor
>>    SYNOPSIS
>>     /usr/etc/halt [ -oqy ]
>>    DESCRIPTION
>>         halt writes out any information pending to the disks and then
>>         stops the processor.
>>          halt normally logs the system shutdown to the system log
>>           daemon, syslogd(8), and places a shutdown record in the
>>           login accounting file Ivar/admlwtmp.
>>           These actions are inhibited if the -0 or -q options are
>present.
>>
>> The BSD 4.3 (that ran on VAXen) man pages say largely similar things:
>>
>>
>>
>https://www.freebsd.org/cgi/man.cgi?query=halt&apropos=0&sektion=0&manpath=4.3BSD+Reno&arch=default&format=html
>>
>>
>ok, so it does a sync then hard halts, but it doesn't gracefully exit
>services, or unmount file systems.