Mac OS X shutdown vs sleep mode

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.

On Jul 8, 2009, at 5:50 AM, Bill Rowe wrote:

> 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.

Launchd can do many things cron can't but there are some schedules
that are easier to do in cron. Also Launchd doesn't like warnings or
errors from the program or script being run. If you look in /var/log/
launchd.log you may see messages like this: "7 more failures without
living at least 60 seconds will cause job removal." Launchd keeps
count of how many times a particular operation has "failed" by its
criteria and will unload that particular Launchd schedule after 10
failures. But my script runs for more than 60 seconds and does not
have an error daily but does give a warning, its making a backup but
doesn't have permission to read one of the sub-directories.

My point is not to bring up my particular problem but to point out
that Launchd can silently stop running a schedule, something cron will
not do.

On Wed, Jul 8, 2009 at 2:50 AM, Bill Rowe<readlistssbcglobal.net> wrote:
> 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.

Please don't assume that Dan was correct without checking. (Note: Dan
is *almost* always correct.)

It is easy to check. After the machine has been off overnight, and
you've given it a decent chance to catch up, run the Console
application. (/Applications/Utilities/Console). Verifiy that there is
a list of logs at the left of the window (if not, select View-->Show
Log List.

In the left (log list) pane, scroll down to and select the "daily.out"
log (under the /var/log heading). The end of the daily.out log will
be shown. (If the log is empty or missing, you're done, the daily
maintenance has never been run.) Note that the last non-blank line
reads

-- End of daily output --

Scroll up to the next instance of that line. Below that are the date
and time the daily script ran...on this machine now that is

Wed Jul 8 03:15:00 PDT 2009

If the date on your machine is old, it means that the maintenance
scirpts are not run when the machine is off at the time they should
run. That is the case on my laptop, where the date and time are Jul 1
17:29. (I let the machine sleep overnight June 30-->July 1 to get the
monthly maintenance done, but didn't wake it up until after work (for
the first time in 2 months, which in turn was the first time in 10
months).

You can do the same check on weekly.out and monthly.out (clever Unix
naming). Note that YMMV: the laptop is an original MacBook running
10.5.7, in case either fact matters.

Off topic:
Hmmm...on my iMac ("this machine" above), ~/Library/Logs/CrashReporter
contains a bunch of
   AdobeResourceSynchronizer_<date>-<PID>_<machine name>.crash
files. From last year. Thanks, Adobe. It's clearly cleanup time. And,
Console insists that the disclosure triangles in the log list all be
"open" on the iMac, so there is lots of scrolling. Thanks, Apple--I
guess there is something you want me to see.

  --John

Thanks for confirming this. At one time I used to leave my computer on over the weekend, now and again, to let it run its scripts. Then I discovered Macaroni. Now I don't need to bother doing anything at all. It's not life-changing but it's certainly a welcome development!

On 7/8/2009 3:03 PM, "John Baxter" 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?
>>
...
>> 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.
>
> Please don't assume that Dan was correct without checking. (Note: Dan
> is *almost* always correct.)

Many (including myself) might disagree ;)


> It is easy to check. After the machine has been off overnight, and
> you've given it a decent chance to catch up...

Note that this won't always happen immediately. For example, on my Desktop
Mac, which sleeps all night, my daily routine wasn't run today until
10:07am.


It's also worth clarifying that if you turn your Mac *off* at night, the
scripts may not run automatically during the day; if you want to be sure the
scripts run, put your Mac to sleep at night instead of shutting it down.
(John alluded to this in his message, but I wanted to emphasize the point.)


Finally, keep in mind that while these scripts are useful, for most users it
wouldn't be a tragedy if they *never* run:

<http://www.macworld.com/article/133684/2008/06/maintenance_intro.html>

On Jul 8, 2009, at 2:50 AM, Bill Rowe wrote:

> 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.

You need to be a little careful here. Dan didn't say the scripts
would run "at the next available opportunity"; he said they would "run
sometime after you wake up the computer." In fact, if you regularly
shut down your computer, the scripts may not run for days, weeks, or
ever. For instance, my mother uses her iMac for several hours every
day and shuts it down every night. On her system, daily.log shows the
daily script ran on June 8th and then on July 3rd.

The way the timing works is described here:

<http://www.thexlab.com/faqs/maintscripts.html>

Of course, if the scripts don't run often, it's not really that big of
a deal. They mostly just rotate logs and clean up temporary files.
With the spacious drives of today, it's not as critical that these
scripts be run so regularly.

On 9/07/2009 8:54 PM, "Dan Frakes" <danfrakesmac.com> spake thus:

> It's also worth clarifying that if you turn your Mac *off* at night, the
> scripts may not run automatically during the day; if you want to be sure the
> scripts run, put your Mac to sleep at night instead of shutting it down.

The same also applies to safe sleep (hibernate), as this also effectively
switches the machine off. I discovered this after switching my Power Mac
over to this using the pmset command. Normally my machine used to get woken
up in the middle of the night to run the maintenance tasks by a wake-on-LAN
request from my DNS server, but with hibernate that no longer works :(

--
Nigel Stanger