What is the difference between halt , poweroff ,shutdown

[rsiddharth]

What is the difference between the 'halt' , 'poweroff' and shutdown commands ?.

I 'manned' these commands in terminal , but wouldn't get what I was looking for - the difference , nor could I infer . I also googled ,hoping to find something that might clear the ambiguity . I did come across a thread in linuxforums.org dealing with the same topic and one of the posts there read :

I am using red hat 5
I guess i understood the use( plz correct me If I am wrong)
shutdown - is for shutting down the server
poweroff- is for shutting down the client

I wouldn't understand what this would mean to a Desktop Computer .
Can anyone here explain me precisely what this means - What is the Difference ? .
I Thank you .

[HermanAB]

Same difference - They all transition to runlevel 6.

[rsiddharth]

Same difference - They all transition to runlevel 6.

Thank you HermanAB , but can you explain it in a way that a lay user may understand - what is 'runlevel 6' ??

[wojox]

http://en.wikipedia.org/wiki/Runlevel#Ubuntu

shutdown -r now = to reboot the system
shutdown -h now = to close the system

halt -p = shut and turnoff the system
halt = to close the system

reboot = to reboot the system

[rsiddharth]

Thank you wojox for making me understand what Runlevels actually are .

I think i am slowly getting the answers ,but my ambiguity over the difference still remains .

the difference between halt and shutdown -h now is made clear by wojox's post here , but what is the difference between 'closing the system' and ' shut and turn off the system ' .

[shanxk8]

Hello all,

New user to Ubuntu here. I've found the posts and contributors on this forum very helpful in getting an old box up & running with Ubuntu. (Ubuntu actually was up and running well on its own, Impressively) I've been able to sort out some issues with mounting an external HDD and setting up a share of that drive.

I have noticed issue with shutdown on that computer though. Ubuntu seems to shutdown to an Ubuntu screen with an empty (all black) progress bar, but the computer does not power off (leaving a fan, or two, still whirring away inside the case and LEDs on the front still on).

What operation does the shutdown button on the upper panel perform? (halt, shutdown, etc.)

Ideas?

I tried the command shutdown -H based on another thread i found, with the same end result.
Next time I'm on there I will have to try halt to see if that is the solution.

Thanks,
David

[unutbu]

Older machines sometimes do not work completely with acpi. The old way of shutting down was to use a module called apm. The module is still available, you just have to set it up. Here are instructions on how to do that:

http://ubuntuforums.org/showpost.php...63&postcount=5

[shanxk8]

I did some reading about acpi as well, a post i came across suggested adding acpi=force to grub/menu.lst
http://ubuntuforums.org/showthread.p...plete+shutdown

I will look into that apm module.

Thanks

[unutbu]

There are a couple of different reasons why shutdown doesn't work for some people. This leads to a couple of different possible solutions. Here is a catalog of various solutions that have worked for certain people:

http://ubuntuforums.org/showpost.php...7&postcount=28

[dcstar]

Same difference - They all transition to runlevel 6.

Runlevel 6 reboots a Linux/Unix system, runlevel 0 shuts it down:

man telinit