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Power Loss Re-Boots

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  Power Loss Re-Boots gtr <xxx@yyy.zzz> - 2014-06-19 07:22 -0700
    Re: Power Loss Re-Boots J Burns <burns4@nowhere.com> - 2014-06-19 11:31 -0400
      Re: Power Loss Re-Boots Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-06-19 11:35 -0400
      Re: Power Loss Re-Boots Your Name <YourName@YourISP.com> - 2014-06-20 09:18 +1200
    Re: Power Loss Re-Boots Jolly Roger <jollyroger@pobox.com> - 2014-06-19 16:19 +0000
      Re: Power Loss Re-Boots Michael Vilain <vilain@NOspamcop.net> - 2014-06-19 21:10 -0700
    Re: Power Loss Re-Boots Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-06-19 18:15 +0000
      Re: Power Loss Re-Boots gtr <xxx@yyy.zzz> - 2014-06-20 07:37 -0700

#61120 — Power Loss Re-Boots

We lost power a number of times yesterday, and each time the computers 
in the house rebooted when the power came back up again.

Is there any potential problems that result from this kind of "turning 
off" of the computer?

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#61123

On 6/19/14, 10:22 AM, gtr wrote:
> We lost power a number of times yesterday, and each time the computers
> in the house rebooted when the power came back up again.
>
> Is there any potential problems that result from this kind of "turning
> off" of the computer?
>
>
I haven't had a problem in years.  I give the credit to journaling.  If 
a file is encrypted, I've read that I could lose it.  A power 
interruption could cause heads to crash, but maybe modern disks are 
designed to reduce the possibility.

I don't have my Mac set to restart automatically because I'm afraid of 
what could happen if the power flickers shortly after coming back on. 
I've read that flickering can be more dangerous than a simple interruption.

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#61125

On 2014.06.19, 11:31 , J Burns wrote:
> On 6/19/14, 10:22 AM, gtr wrote:
>> We lost power a number of times yesterday, and each time the computers
>> in the house rebooted when the power came back up again.
>>
>> Is there any potential problems that result from this kind of "turning
>> off" of the computer?
>>
>>
> I haven't had a problem in years.  I give the credit to journaling.  If
> a file is encrypted, I've read that I could lose it.  A power
> interruption could cause heads to crash, but maybe modern disks are
> designed to reduce the possibility.
>
> I don't have my Mac set to restart automatically because I'm afraid of
> what could happen if the power flickers shortly after coming back on.
> I've read that flickering can be more dangerous than a simple interruption.

I've slapped a UPS in there.

And a good thing.  When my new laser printer starts up it sucks the line 
voltage down enough to trip the UPS into battery mode for a few seconds. 
  That printer will be relocated soon...

At a company I worked at every computer had a UPS because factory ops 
could suck the mains voltage down long enough to cause computers to 
power off.

A UPS is a wise bit of kit.  (I have my computer and one of my external 
disk sets on it).

-- 
I was born a 1%er - I'm just more equal than the rest.

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#61145

In article <lnuvnu$a44$1@dont-email.me>, J Burns <burns4@nowhere.com>
wrote:
> On 6/19/14, 10:22 AM, gtr wrote:
> > We lost power a number of times yesterday, and each time the computers
> > in the house rebooted when the power came back up again.
> >
> > Is there any potential problems that result from this kind of "turning
> > off" of the computer?
> 
> I haven't had a problem in years.  I give the credit to journaling.  If 
> a file is encrypted, I've read that I could lose it.  A power 
> interruption could cause heads to crash, but maybe modern disks are 
> designed to reduce the possibility.

You may lose whatever you're working on that hasn't been saved or in
the process of saving, although the "auto-save" feature may help there.



> I don't have my Mac set to restart automatically because I'm afraid of 
> what could happen if the power flickers shortly after coming back on. 
> I've read that flickering can be more dangerous than a simple interruption.

When the power goes out (or during a big lightning storm) you're
advised to go around turning off devices at the wall to stop the surges
doing any damage. Some surges can jump the wall socket's off switch and
even a multi-socket powerboard's in-built protection.

Sometimes just before the power goes out you also get flickering surges.

An UPS box may help to give the computer enough time to shutdown
properly.

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#61129

On 2014-06-19, gtr <xxx@yyy.zzz> wrote:
> We lost power a number of times yesterday, and each time the computers 
> in the house rebooted when the power came back up again.
>
> Is there any potential problems that result from this kind of "turning 
> off" of the computer?

This is why uninterruptible power supplies UPSs exist. With a UPS
connected to your computer, the computer can automatically and
gracefully shut down when power goes out and the UPS battery is drained.
Removing power while the operating system and applications are running
isn't a good idea. In most cases, the operating system can recover, but
you run the risk of losing data on disk, and potentially causing some
badly-written applications to malfunction, possibly in ways not
obviously attributable to the power yank.

-- 
E-mail sent to this address may be devoured by my ravenous SPAM filter.
I often ignore posts from Google. Use a real news client instead.

JR

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#61178

In article <c0ggspFg7deU2@mid.individual.net>,
 Jolly Roger <jollyroger@pobox.com> wrote:

> On 2014-06-19, gtr <xxx@yyy.zzz> wrote:
> > We lost power a number of times yesterday, and each time the computers 
> > in the house rebooted when the power came back up again.
> >
> > Is there any potential problems that result from this kind of "turning 
> > off" of the computer?
> 
> This is why uninterruptible power supplies UPSs exist. With a UPS
> connected to your computer, the computer can automatically and
> gracefully shut down when power goes out and the UPS battery is drained.
> Removing power while the operating system and applications are running
> isn't a good idea. In most cases, the operating system can recover, but
> you run the risk of losing data on disk, and potentially causing some
> badly-written applications to malfunction, possibly in ways not
> obviously attributable to the power yank.

While I can't give you specifics, I have had a Macintosh running 
different versions of MacOS fail to boot if it's "bounced" a couple 
times. I'm not talking about physically, but electrically having the 
power cycled in mid-boot repeatedly.  

My 10.2 system failed to fsck after I bounced it trying to get it to 
boot in single user, so I reinstalled from media.

A slightly older PowerBook (it had a DVD but no Thunderbolt port) 
apparently had Lion installed on it.  A manager got it back from an 
departed employee and wanted the root password.  It predated both me and 
my Boss's tenure at the company and we tried rebooting it.  It didn't 
reboot gacefully, so I used a "rescue disk" I had that boots Mountain 
Lion with a bunch of utilities.  The disk had significant damage that 
Disk Utility couldn't repair, so I did a new install of Mountain Lion 
from a DVD I burned from the "Install Mountain Lion.app".

My guess is that some of the file caching used during boot is sensitive 
and can corrupt the disk.  But I have not hard data on it.

Bottom line, buy a UPS or suffer the consequences.  If you plug any of 
the new APCs into the Mac through the USB, it will recognize it and shut 
the machine down if it figures out it's running on battery that's about 
to crap out.

-- 
DeeDee, don't press that button!  DeeDee!  NO!  Dee...
[I filter all Goggle Groups posts, so any reply may be automatically ignored]

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#61142

In message <2014061907222835718-xxx@yyyzzz> 
  gtr <xxx@yyy.zzz> wrote:
> We lost power a number of times yesterday, and each time the computers 
> in the house rebooted when the power came back up again.

> Is there any potential problems that result from this kind of "turning 
> off" of the computer?

Yes, if the power outages are close together. Depends on the hardware,
the wiring, how long the power is out, one what sort of a surge you get
when it comes back up.

Any non-laptop should be on a UPS to cover these sorts of events. You
can spend $30 or so for a cheapo UPS that will not keep your computer on
more than 4 or 5 minutes, but that's more than enough for this type of
protection.

The UPSs generally also act as line conditioners/voltage regulators, so
they're good to have even when your power doesn't go off.

-- 
Dinner will be ready when the smoke alarm goes off.

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#61195

On 2014-06-19 18:15:31 +0000, Lewis said:

> In message <2014061907222835718-xxx@yyyzzz>
>   gtr <xxx@yyy.zzz> wrote:
>> We lost power a number of times yesterday, and each time the computers
>> in the house rebooted when the power came back up again.
> 
>> Is there any potential problems that result from this kind of "turning
>> off" of the computer?
> 
> Yes, if the power outages are close together. Depends on the hardware,
> the wiring, how long the power is out, one what sort of a surge you get
> when it comes back up.
> 
> Any non-laptop should be on a UPS to cover these sorts of events. You
> can spend $30 or so for a cheapo UPS that will not keep your computer on
> more than 4 or 5 minutes, but that's more than enough for this type of
> protection.
> 
> The UPSs generally also act as line conditioners/voltage regulators, so
> they're good to have even when your power doesn't go off.

Thanks all for the input.

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