Mac Forum / Applications / Mac Applications / May 2008

The forced shutdown is not as radical as pulling the power cord out of
the wall, but it's close. I _think_ a few system cleanup tasks take
place, like flushing the write cache and parking the read/write heads,
but not very much else. You certainly don't get the opportunity to save
your work in open apps.

I don't think you'll have a problem unless your wife decides to rest her
elbow directly on the power button while she's pondering her work. Even
then, you have to hold the button for 5-10 seconds before the machine
shuts down. I'm sure your wife is a competent person, so if you just
tell her to stay away from the power button, you should be fine.

--Fred

The "forced shutdown" from holding down the power button protects the
hard drive from damage, but does nothing about saving any open
documents. So it is better than pulling the power cord. The machine
should start up normally after a forced shutdown of this type.

Normal shutdown asks if you want to save changes in documents if it
finds any open with unsaved changes.

You have to hold the power button down for a fairly long time -- several
seconds -- before the forced shutdown will occur, so there is really not
much danger of causing it inadvertently.

The reason the forced shutdown feature exists is to allow a safe
recovery -- safe in the sense of avoiding hard drive damage -- from the
machine totally freezing up and not responding at all to any commands.
This can occur from what is called "kernel panic" where the operating
system loses track of what it is doing. This is quite rare but can
happen.

Occasionally an individual application may freeze. It may be necessary
to force quit the application. This can be done without forcing a system
shutdown, either by selecting "Force Quit" from the Apple menu, or
pressing the key combination Option-Command-Escape. "Command" is the
Apple-Pretzel key. When you force quit an application, unsaved changes
of any open documents in that application will be lost, but otherwise
the system will be just fine.

It's as if you ripped the power cord from thee wall. It interrupts power
to the system. The system gets no warning and has no time to prepare.
It's not healthy to do this unless absolutely necessary.

You have to literally hold it down for like 4 seconds.  It'll be very
hard for someone to do this accidentally.

Don't you ever install security fixes then?  Some of those (especially
the QuickTime ones) require a restart.

For me (10.5.2, 24" iMac Core 2 Duo), it's on the Options pane.

IIRC, some Macs don't allow that setting. It's model-specific, I believe.

Thanks. What I was concerned about was whether or not, if the power
button was pushed, the system would immediately go into a power shutdown
or throw up a dialog box asking what to do.
I finally tried it after reading all the answers here. On the Macbook
Pro with Leopard, pushing the power button does indeed throw you a
dialog box asking whether you are sure you want to shut down the system,
so this in effect answers my fears about what would happen if my wife
accidentally pushed the button, forgetting to shut down properly.
The dialog box gives you a chance to cancel the function, sleep the
computer, or shut it down.
I guess the only additional thing I really need to know at this point is
 if you choose to shut down the computer from this dialog box; is the
shutdown a normal shutdown as though you shut down starting with the
apple icon drop down menu??
From what I've been reading, if you choose "shutdown" at that point,
it's the same thing as pulling the plug????????????????????

Uggg! WoW has frozen my 24" iMac MANY times! Grrr... I'm really sick of
that as I'm the sort of player who'll suffer a few less FPS to still
have everything running in the background and easily accessible.

Regards,
Jamie Kahn Genet