Mac OS X shutdown vs sleep mode

I know, I know that sleep is appropriate for laptops and indeed, all Macs, but I find one problem with sleep mode and MacBooks and MacBook Pros.

I put my sleeping computer in my backpack/portable office/shop and occasionally when I get to my destination, I find that the computer has been awakened, is hot as a two dollar pistol and the battery is run down. I believe the reason is that the Sudden Motion Sensor, which is designed to prevent hard drive damage if the computer is dropped, is activated by a bumpy car ride and may be kept awake by some web page looking for updates.

Anyone else have such an experience? Think my explanation of the Sudden Motion Sensor is reasonable or probable?

Chris Harnish

On Tue, Jun 30, 2009 at 2:08 PM, Chris Harnish<charnishmac.com> wrote:
> I put my sleeping computer in my backpack/portable office/shop and occasionally when I get to
> my destination, I find that the computer has been awakened, is hot as a two dollar pistol and the
> battery is run down. I believe the reason is that the Sudden Motion Sensor, which is designed to
> prevent hard drive damage if the computer is dropped, is activated by a bumpy car ride and may
> be kept awake by some web page looking for updates.
>
> Anyone else have such an experience? Think my explanation of the Sudden Motion Sensor is
> reasonable or probable?

That's not supposed to happen, and it may be worth bringing it in to
get checked out.

My understanding is that when the laptop is sleeping, the hard drive's
heads should be parked so that they can't damage the platters if the
drive gets jostled; the Sudden Motion Sensor (SMS) only comes into
play when the machine is fully turned on.

If the laptop is turning back on while the lid is closed, it may be
that you're having a malfunction with either the Reed switch (the
sensor that detects when the lid gets closed or opened), the logic
board ["motherboard"], the wiring that connects them, etc. Or, heck,
maybe you have something metallic or magnetic in your backpack that is
interfering with the Reed switch and causing it to come out of sleep
mode.

The easiest thing you can try, short of a hardware repair, is a System
Management Controller (SMC) reset. The procedure for doing this is
different on different models, but regardless of the model, it's
documented on Apple's support site: http://support.apple.com/kb/HT1411

If you're still seeing this behavior after an SMC reset, my guess is
that it's a hardware fault, and you need to get it fixed.


--
Chris Devers

On Jun 30, 2009, at 11:08 AM, airbusdriver wrote:

> While the original poster mentioned a laptop, this question comes up
> often and is certainly not limited to portable machines. There will
> always be those in each camp, with any type/make of computer. My
> feeling is that, unless your machine is doing something useful, turn
> it off. Period.
>
> OTOH, I make sure that all Macs I support ARE doing something
> useful. My choice is Stanford University's Foldinghome <http://folding.stanford.edu/
> > with the Team Mac OSX <http://www.teammacosx.com/> distributed
> computing system. But there are many other similar programs. What
> I'm talking about is a distributed computer set up that works on
> some kind of project that has real opportunities of making a
> difference in health, science or something important to mankind.
> Find one that you'd like to support <http://en.wikipedia.org/wiki/List_of_distributed_computing_projects
> > and help someone, today. :-)

I have Berkeley's Setihome running on my iMac and plan to get it
going on some of my other Macs. Boinc.berkeley.edu has numerous
others besides Seti.

GO BEARS!!

Dave Clark
www.clarklawfirm.com
http://daveclarkimages.smugmug.com
http://twitter.com/dave30c

Den 30/06/2009 kl. 20.08 skrev Chris Harnish:

> I put my sleeping computer in my backpack/portable office/shop and
> occasionally when I get to my destination, I find that the computer
> has been awakened, is hot as a two dollar pistol and the battery is
> run down. I believe the reason is that the Sudden Motion Sensor,
> which is designed to prevent hard drive damage if the computer is
> dropped, is activated by a bumpy car ride and may be kept awake by
> some web page looking for updates.
>
> Anyone else have such an experience? Think my explanation of the
> Sudden Motion Sensor is reasonable or probable?

I only had that experience a very few times. The first time was with
my old Clamshell, where I had installed an airport card (many years
ago :-) ), and had failed to lock down the keyboard properly, so that
sleep never occured when I closed the lid. With my Powerbook and later
Macbook Pro, I have had the issue where the latch had gone open for
some reason and the computer had sprung awake again. (yes, they are
very worn...) I have also on a few occassions over the years seen a
process refusing to go to sleep and that way keeping the computer
alive after closing the lid.

I don't think any of my laptops have been shut down for longer time
than it takes to change the hard drive or similar ever: sleep is the
way to go. Even for changing battery I just let them deep sleep.

Best,

Kim

On 2009-07-01, at 06:08, Chris Harnish wrote:

> I put my sleeping computer in my backpack/portable office/shop and
> occasionally when I get to my destination, I find that the computer
> has been awakened, is hot as a two dollar pistol and the battery is
> run down. I believe the reason is that the Sudden Motion Sensor,
> which is designed to prevent hard drive damage if the computer is
> dropped, is activated by a bumpy car ride and may be kept awake by
> some web page looking for updates.

Seems more likely to be another trigger. I would put the Mac to sleep
and see if you can recreate the problem: do things like squeeze and
warp the case to try and activate keys/trackpad. Don't be too harsh,
nothing more than would happen in your bag!

There's also messages in the system log about what caused the wake
event though they can be hard to interpret.

Are you sure it's all the way asleep? I've had occasions when I closed
the lid but it didn't actually sleep . . .so if I'm putting it in the
case I hit the power button and select sleep . . .then wait until the
screen goes black and the drive spins down before closing the lid.

On 6/30/09 at 11:08 AM, patroshhotmail.com (Paul Atroshenko) wrote:

>What happens if your computer is in sleep mode while you are away on
>vacation and your local area is hit by a massive thunderstorm?

>Does sleep mode protect your motherboard from being zapped?

The short answer is no, the function of sleep mode is not to
protect your system from voltage transients on line power. Of
course, if the system is *disconnected* from AC power, there can
be no issue. But if the system is connected to AC power directly
(no surge protector) then there is some level of risk regardless
of sleep mode.

Note, the issue of protecting against line transients is not
restricted to computers. Any modern electronic device simply
will not like large voltage transients. The amount of damage
done (if any) will vary greatly from device to device and is
strongly dependent on design details of the device that are not
usually provided to the end user.

On 30-Jun-2009, at 12:08, Sander Tekelenburg wrote:
> At 15:08 -0700 UTC, on 2009-06-29, LuKreme wrote:
>
>> On a laptop, there's no reason to ever shutdown.
>
> Well, it still does draw *some* power. If even just to for the sleep
> light.

Not if you pop the battery. Safe Sleep is *brilliant*

> I thought "safe sleep" (aka "hybernate" -- writing contents of RAM
> to disk),
> is the default since about 1 or 2 years.

Wasn't the default on my brand new MacBook Pro.

 On Jun 30, 2009, at 1:08 PM, Chris Harnish wrote:
> I put my sleeping computer in my backpack/portable office/shop and
> occasionally when I get to my destination, I find that the computer
> has been awakened, is hot as a two dollar pistol and the battery is
> run down. I believe the reason is that the Sudden Motion Sensor,
> which is designed to prevent hard drive damage if the computer is
> dropped, is activated by a bumpy car ride and may be kept awake by
> some web page looking for updates.
>
> Anyone else have such an experience? Think my explanation of the
> Sudden Motion Sensor is reasonable or probable?

You may want to try to type "sudo pmset lidwake 0" (without the
quotes) or use a utility like iLid
<http://www.macupdate.com/info.php/id/24703/ilid> that does the same
thing.

I used it on my Al Powerbook to prevent it from wakening when the lid
was jostled. It will wake on keytouch or spacebar but not on opening
or closing the lid. I don't know if the sensor wakes the MacBook or
not, but it is probably a lid issue.

Ray

--On July 1, 2009 12:22:27 PM -0700 Bill Rowe <readlistssbcglobal.net>
wrote:

> Note, the issue of protecting against line transients is not
> restricted to computers. Any modern electronic device simply
> will not like large voltage transients. The amount of damage
> done (if any) will vary greatly from device to device and is
> strongly dependent on design details of the device that are not
> usually provided to the end user.

Some power companies are offering whole house surge protection. Mine does
for $5.95 a month, with a $10,000 annual warranty. Not all power companies
have this, but you might check with yours. (in kansas city the rate for
surge protection isn't part of the regulated rates so it can go up, but it
hasn't so far while our power rates have gone up several times.)

<http://www.kcpl.com/residential/Meter_Pro.html>

Might sound expensive compared to a couple of surge protectors but it
should be noted that:
a) it protects other equipment too such as your refrigerator and air
conditioner.
b) you need to replace those surge strips every couple of years (more
frequently if you live in an area with a lot of surges) anyway. This plan
includes maintenance of the surge system.

Meter based protection only protects against surges external to the house,
but if your house takes a direct hit from lightning you probably don't need
to worry about the voltage surge. If a large piece of equipment fails
inside the house in such a way that it causes a voltage surge, then you
might have a problem. These are fairly rare compared to lightning storms
(in the mid-west at least.)

Kevin

LuKreme wrote:

> On a laptop, there's no reason to ever shutdown.

In theory yes. But I've found that for Leopard and Tiger many Mac laptops will get confused after a while if you keep putting them to sleep connected to one wireless network and wake them somewhere where there's no network or a different network. For whatever reason at some point doing this you'll get a system that will not wake up until powered off then back on.

Also another issues related to this is folks who have their wireless setup remember every network they've joined. Then they start complaining that starting up or waking up seems to take a very long time. I go in and notice the 40 or so networks it's searching for to see if any of them are around before asking what you might want to do. Purging this list of all but a few clears this up very fast.

David

On 1-Jul-2009, at 13:26, LuKreme wrote:
> On 30-Jun-2009, at 12:08, Sander Tekelenburg wrote:
>> I thought "safe sleep" (aka "hybernate" -- writing contents of RAM
>> to disk),
>> is the default since about 1 or 2 years.
>
> Wasn't the default on my brand new MacBook Pro.

This was wrong. I was thrown by the fact there's no way to pop the
battery, so no way to force safe sleep mode.

Oops. The default is safe sleep.

At 7/2/2009 08:21 AM -0700, Kevin van Haaren wrote:
>Some power companies are offering whole house surge protection. Mine does
>for $5.95 a month, with a $10,000 annual warranty. [...]
>
><http://www.kcpl.com/residential/Meter_Pro.html>
>
>Might sound expensive compared to a couple of surge protectors but it
>should be noted that:
>a) it protects other equipment too such as your refrigerator and air
>conditioner.

Interesting, but I'm not very impressed.

The FAQ makes it clear that only corded appliances are covered (thus
not your central A/C), and only up to $750/appliance (not enough for
computers and many TVs and stereos). They don't say how a claim will
be evaluated to distinguish between external and internal surges, and
they talk a lot about internal surges. They don't cover direct
strikes at all, where localized surge protection might at least have
a chance of lessening the damage.

I've also had the experience of lightning damage due to a strike
about 100 yards away. The damage was to an Ethernet cord, not via
powerline, so I conclude that it resulted from a voltage induced over
the 50' length of the line. Of course I don't know how large that
voltage was, and it may not have been enough to cause problems on a
power line. But it makes me want to have surge protection closer to
the equipment.

Edward
--
Art works by Melynda Reid: http://paleo.org

At 6/29/2009 03:08 PM -0700, Kevin van Haaren wrote:
>1) Just sitting there a windows machine tends to be vulnerable to attacks.

Not if it's behind a NAT router with no port forwarding set up.
Unfortunately most cable and DSL modems don't do NAT by default, but
adding a cheap router enhances safety from this kind of attack
greatly. In any case, on current systems, Windows Firewall by default
blocks most incoming connections.

>2) If you have been infected most likely your machine is being used
>as part of a botnet to send spam.

If that's the case, then you are beyond the kind of help being
offered here. ;-)

>Also if your machine crashes when not in use (an unfortunately
>frequent occurrence on Windows)

I haven't seen that happen under XP or Vista, except when caused by
hardware problems.

Edward
--
Art works by Melynda Reid: http://paleo.org

--On July 6, 2009 9:55:53 AM -0700 Edward Reid <edwardpaleo.org> wrote:

> At 7/2/2009 08:21 AM -0700, Kevin van Haaren wrote:
>> Some power companies are offering whole house surge protection. Mine does
>> for $5.95 a month, with a $10,000 annual warranty. [...]

> The FAQ makes it clear that only corded appliances are covered (thus
> not your central A/C)

I noticed this after I sent the message but to be honest I can't figure out
how they would accomplish this. Perhaps the warranty doesn't cover the A/C
or furnace but electrically there isn't a way to have a meter based surge
suppressor that doesn't protect everything downstream. Most houses have 2
phases of power, it's possible they're only protecting 1 phase but this
doesn't make sense either, I've got outlets for corded appliances on both
phases. And the A/C and such tie into both phases.

>, and only up to $750/appliance (not enough for
> computers and many TVs and stereos).

I missed this, it is a setback to the program (I'm not on it because our
power has been pretty solid since an upgrade a few years back in the
neighborhood).

> They don't say how a claim will
> be evaluated to distinguish between external and internal surges, and
> they talk a lot about internal surges. They don't cover direct
> strikes at all, where localized surge protection might at least have
> a chance of lessening the damage.

The protection at the meter can indicate if a surge went through from the
outside in. They can verify through that (if you have to take their word is
another questions.)

Direct lighting strike - uh no. That surge suppressor on your outlet isn't
going to do anything, it can't suppress anything near the size of a direct
lightning bolt (even a small one) and they also react way to slow.


> I've also had the experience of lightning damage due to a strike
> about 100 yards away. The damage was to an Ethernet cord, not via
> powerline, so I conclude that it resulted from a voltage induced over
> the 50' length of the line.

Actually it was probably induced in the lines outside the house and
traveled in via the wires (another plus for the wireless and fiber
networks). Current from a lighting strikes can actually travel through the
ground for a surprising distance before completely dissipating.

There are surge suppressors for phone lines as well (cable lines can also
have problems, BTW)

--On July 6, 2009 9:55:53 AM -0700 Edward Reid <edwardpaleo.org> wrote:

> At 6/29/2009 03:08 PM -0700, Kevin van Haaren wrote:
>> 1) Just sitting there a windows machine tends to be vulnerable to
>> attacks.
>
> Not if it's behind a NAT router with no port forwarding set up.
> Unfortunately most cable and DSL modems don't do NAT by default, but
> adding a cheap router enhances safety from this kind of attack
> greatly. In any case, on current systems, Windows Firewall by default
> blocks most incoming connections.

Bad idea to assume this has occurred. About the only time I find Windows
people with home routers is when they wanted wireless and got a router with
it by default, or when a more technical friend set it up.

Also you have to disable UPnP (typically on by default) or the computer can
configure port forwarding on it's own.

Also if you happen to leave IM running (or have an IM notification
continuously running) then ports are open and vulnerable to certain attacks.


>> Also if your machine crashes when not in use (an unfortunately
>> frequent occurrence on Windows)
>
> I haven't seen that happen under XP or Vista, except when caused by
> hardware problems.

Or a bad anti-virus auto-update, or a bad windows auto-update, or a run
away process that finally ate up all memory. I've seen all of these and
more.

Dan, this is big news for me! I always turn my Mac off at night, so the Unix maintenance routines will never run at the proper time. But now it seems I don't need to fret about this, I don't need to use a maintenance utility?

--On July 7, 2009 12:46:59 AM -0700 Kevin van Haaren <kevinvanhaaren.net>
wrote:

>> I've also had the experience of lightning damage due to a strike
>> about 100 yards away. The damage was to an Ethernet cord, not via
>> powerline, so I conclude that it resulted from a voltage induced over
>> the 50' length of the line.
>
> Actually it was probably induced in the lines outside the house and
> traveled in via the wires (another plus for the wireless and fiber
> networks). Current from a lighting strikes can actually travel through the
> ground for a surprising distance before completely dissipating.

Well that was stupid on my part. Your ethernet cable doesn't go outside (I
assume). I was thinking telephone wires. It is possible the surge came in
via DSL or cable modem, but unless those devices were wiped out too, and
passed the surge onto the ethernet, you're probably right on it being
induced in the ethernet cable.

On Tue, Jul 7, 2009 at 3:54 PM, Kevin van Haaren<kevinvanhaaren.net> wrote:
> Your ethernet cable doesn't go outside (I assume).

In fact, mine does, due to outside being the easiest way to run cable
from one part of the house to another. I had to get the right sort of
Ethernet cable, and indeed, a lightning strike (or rather, the
induction from one) did once blow out an Ethernet port on my Mac.

http://db.tidbits.com/article/7737

cheers... -Adam

On 7/7/09 at 7:47 AM, peter.drakefreeuk.com (Peter Drake) wrote:

>Dan, this is big news for me! I always turn my Mac off at night, so
>the Unix maintenance routines will never run at the proper time. But
>now it seems I don't need to fret about this, I don't need to use a
>maintenance utility?

I had not been aware moving the daily/weekly/monthly scripts
from cron to lauchd as done in 10.5 made it so that these
scripts would run at the next available opportunity should my
laptop be turned off overnight until Dan Frakes mentioned it here.

I had been running Macaroni which simply got migrated from
previous versions of OS X when I upgraded to 10.5. So, I tried a
test by disabling Macaroni and shutting my system down
overnight. A check of the logs after restarting the next morning
verified the daily script did indeed run at the next opportunity.

So, yes there is no need to use a separate maintenance utility
for these scripts. And if you grap a copy of the freeware
program Lingon, it is simple to add other things to launchd that
you might have previously run under cron.