Mac OS X shutdown vs sleep mode

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

On 9/07/2009 8:54 PM, "Conrad Hirano" <tidbitshirano.fastmail.fm> spake
thus:

> 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.

There's also the update of the locate database, which is kind of important
if you use the locate command a lot :) (I find it much more useful than
Spotlight in most cases.)

--
Nigel Stanger

On 7/9/09 at 1:54 AM, danfrakesmac.com (Dan Frakes) wrote:

>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.)

Interesting. I would have not expected this to make much
difference. When I tested this, I did it during the period where
I let the battery run down to re-calibrate it per Apple's
recommendation. So, my machine would have gone into hibernate
(deep sleep) mode rather than being shut down. Inspection of the
logs after my test showed the daily script did run right after
connecting to ac power and re-starting.

Unix scripts - I checked yesterday as suggested by John Baxter, and Console did not show any daily.out, weekly.out or monthly.out logs, after six weeks of running this machine (Mac Mini, OSX 10.5.7) but switching it off overnight.

However, I left it in sleep mode last night, and this morning there's a brand new daily.out log... So it seems you musn't switch off every night, if you care about these scripts running. Various people have suggested it doesn't really matter either way, but I guess I'll let them run occasionally for the sake of clean and tidy housekeeping.

on 7/10/09 01:57, Peter Drake at peter.drakefreeuk.com wrote:

> Unix scripts - I checked yesterday as suggested by John Baxter, and Console
> did not show any daily.out, weekly.out or monthly.out logs, after six weeks of
> running this machine (Mac Mini, OSX 10.5.7) but switching it off overnight.
>
> However, I left it in sleep mode last night, and this morning there's a brand
> new daily.out log... So it seems you musn't switch off every night, if you
> care about these scripts running. Various people have suggested it doesn't
> really matter either way, but I guess I'll let them run occasionally for the
> sake of clean and tidy housekeeping.

I'm sure most of you already know this, but if you feel you must be doubly
sure that these scripts run no matter what you do with your machine at night
take a look at Anacron:

<http://members.cox.net/18james/anacron-tiger.html>

Supposedly not needed with Leopard, but won't do harm. Uses a few
milliseconds to execute every hour.

 
-Al-

--
Al Varnell
Mountain View, CA

At 7/7/2009 12:46 AM -0700, Kevin van Haaren wrote:
>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.

My guess -- and it's only a guess -- is that it's simply another way
of capping their risk, especially since the A/C isn't even the most
vulnerable appliance. I agree, protection at the meter has to protect
everything downstream (and so is valuable for protecting the A/C even
if it isn't insured as part of the program). They don't say the A/C
isn't protected, only that it isn't insured. This indicates their
uncertainty about the reliability of the protection, but the
protection is there.

>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.

Right, protecting only one phase would basically protect less than
half the house, and they would have no way of knowing which phase had
the more expensive stuff plugged in to it. It surely protects both
legs, and also the neutral for that matter. (A normal residential
service entrance has three wires. Though it's described as
single-phase, it's really two phases derived from one phase of the
three phases in the distribution system. The three wires are for the
two phases and a neutral to carry the residual unbalanced load.
Normal 120V circuits are exposed to one phase and neutral, so
protecting the neutral from surges is just as important as protecting
the phases.)

>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).

You already followed up on this, but yes, I agree that it's a strong
point in favor of wireless or fiber for a LAN in lightning-prone
locations, with the advantage increasing with the distance from one
port to another. In my case, the isolation from the phone feed was
even greater than I indicated in my brief description, as the phone
line went to a modem (don't recall which it was POTS or ISDN at the
time) then to an old Mac running routing software under FreeBSD Unix
(this was before off-the-shelf routers came down to a reasonable
price), out another card to Ethernet, and the burnt out card was on
the near or far end of that cable (two occurrences).

>Current from a lighting strikes can actually travel through the
>ground for a surprising distance before completely dissipating.

Yes, in fact modern advice to hikers (or anyone caught outside in a
thunderstorm) is that ground currents are at least as much of a
danger as direct strikes. Thus the old advice to lie down in a ditch
is no longer operative; instead you are advised to crouch and
minimize your contact with the ground, and even to crouch on a
sleeping pad if available.

So I don't know exactly how the electrical field reached the
building. Possibly through the air, possibly as a result of ground
currents under the building, or even a combination.

This was in a mobile home, on piers (thus minimal ground contact) and
a metal roof, but very little metal in the walls or floor. A wire
grid in the walls, or aluminum siding, might create a partial Faraday
cage and protect from this kind of damage. (The fact that the body of
a car forms a Faraday cage is the reason that a car is a relatively
safe place to be in a thunderstorm.)

At 7/7/2009 12:54 PM -0700, David Ross wrote:
>If lightning hit 100 years away your entire house rode a wave of
>1000s of volts.

When you give voltages, you have to give the two points you are
measuring between. Voltage is relative. The voltage near the house
may have been thousands of volts relative to points half a mile away,
but the important voltage is the potential between two pieces of
equipment (where I use "equipment" in the most general sense, to
include power entrances etc as well as computers and appliances). The
farther apart two pieces of equipment are while this "wave" rolls
over, the more likely they are to have a large potential between
them. Your potential can be thousands of volts relative to something
distant, but it it's uniform on the things in question, no current
flows and no damage occurs. This is the principle of the Faraday
cage: no matter what the potential between inside and outside,
everything inside is at the same voltage and thus senses no potential.

Now of course I don't know the actual voltages present in my
incidents. I do know that lightning struck twice in nearly the same
place a couple of years apart, and that NICs on this same cable were
damaged both times, at opposite ends of the cable. And it was the
longest cable in the house by far. Nothing connected within the same
room was damaged. Nothing directly connected to phone lines or power
lines was damaged, not even the modem, which was connected to both.
Small sample with no real data, but suggestive.

>And your Ethernet card damage was most likely due to your internet
>service having a separate service entrance to your house from your
>power source. This allowed the voltage wave to enter your house at
>separate points and create a very short term very high voltage
>potential between various pieces of equipment.

As described above, the damage was on a rather isolated link, not on
anything electrically near the phone service entrance. And in any
case, my point was that voltage potentials can occur without a direct
wire link. Electrical fields exist in vacuums. Transformers work
based on electrical fields "communicating" from one winding to
another which is electrically insulated from the first. The
electrical field from the actual strike, or (as Kevin mentioned) from
ground currents, was likely the cause of this damage, and certainly
could have been. I could have had all phone line and power line
connecters unplugged and still could have suffered damage.

As Kevin said, this gives wireless and fiber networks a significant
advantage in lightning-prone areas. This is usually discussed in
terms of links that have to go outside, but it's possible to suffer
damage on purely inside links as well. In my case, if the link had
been wireless or fiber, there's a very good chance I would have had no damage.

Edward