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Does power failure harm, when sleeping?

Message #1 - Posted 2004/04/21 - Keeper of the Purple Twilight

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

"No urban night is like the night [in NYC]...here is our poetry, for we have pulled down the stars to our will."
- Ezra Pound, poet and critic, 9/18/1912, reflecting on New York City

Message #2 - Posted 2004/04/21 - Steve W. Jackson

Previously, Keeper of the Purple Twilight wrote:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

Probably not. If your settings allow the hard drive to spin down when sleeping, then definitely not.

= Steve =

Steve W. Jackson
Montgomery, Alabama

Message #3 - Posted 2004/04/21 - johnny bobby bee

Steve W. Jackson wrote:

Previously, Keeper of the Purple Twilight wrote:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

Probably not. If your settings allow the hard drive to spin down when sleeping, then definitely not.

question was: 'harm to any files on the hard drive'. not 'harm to the actual HDD itself.
given that -- i'd say definitely yes. there are files still open and other process not yet killed during sleep-mode.
so, i'd say that there is a good chance to harm/corrupt system files if power got cut off even during sleep-mode.

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People would rather live with a problem they cannot solve than accept a solution they cannot understand.

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Message #4 - Posted 2004/04/21 - clvrmnky

On 21/04/2004 6:05 PM, Keeper of the Purple Twilight wrote:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

If by "sleep" you mean total drives-spun-down throbbing-light hibernation mode, then it is highly unlikely that a power-down will affect anything.

When an OS X box goes into hibernation it does quite a bit of housekeeping like saving current application states to disk, flushing all the buffers and journals, parking disks and putting all the hardware into a standby or power-off mode.

In this particular state it is unlikely that anything bad can happen to files on disk simply by cycling the power. All bets are off if the power outage was caused by a massive electrical surge. This is, of course, a different animal altogether.

cm

Message #5 - Posted 2004/04/21 - Keeper of the Purple Twilight

clvrmnky wrote:

On 21/04/2004 6:05 PM, Keeper of the Purple Twilight wrote:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

If by "sleep" you mean total drives-spun-down throbbing-light hibernation mode, then it is highly unlikely that a power-down will affect anything.

By 'sleep' I mean...sleep. How many sleep modes are there? :)

When an OS X box goes into hibernation it does quite a bit of housekeeping like saving current application states to disk, flushing all the buffers and journals, parking disks and putting all the hardware into a standby or power-off mode.

Just to make it clear, we're talking about straight-up "Sleep" mode, accessed by the Apple menu, right? The one right below "Force Quit" and above "Restart"? I ask this 'cos I get the feeling there's something I'm not getting about what "sleep" means...

"No urban night is like the night [in NYC]...here is our poetry, for we have pulled down the stars to our will."
- Ezra Pound, poet and critic, 9/18/1912, reflecting on New York City

Message #6 - Posted 2004/04/21 - Barry Margolin

Previously, Keeper of the Purple Twilight wrote:

clvrmnky wrote:

On 21/04/2004 6:05 PM, Keeper of the Purple Twilight wrote:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

If by "sleep" you mean total drives-spun-down throbbing-light hibernation mode, then it is highly unlikely that a power-down will affect anything.

By 'sleep' I mean...sleep. How many sleep modes are there? :)

There's also "display sleep" and "hard disk sleep". You can find settings for these in the Energy Savers preference.

Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***

Message #7 - Posted 2004/04/22 - Daniel Cohen

Barry Margolin wrote:

By 'sleep' I mean...sleep. How many sleep modes are there? :)

There's also "display sleep" and "hard disk sleep". You can find settings for these in the Energy Savers preference.

Ah, that explains the term "deep sleep" that I've seen used quite a lot. --
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Message #8 - Posted 2004/04/22 - Mathue

Previously, Keeper of the Purple Twilight wrote:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

If you're in OSX land and have disk journaling enabled I don't expect it should cause a problem at all.

MT - Diagonally parked in a parallel universe.

101010

Message #9 - Posted 2004/04/22 - Mathue

Previously, Keeper of the Purple Twilight wrote:

Just to make it clear, we're talking about straight-up "Sleep" mode, accessed by the Apple menu, right? The one right below "Force Quit" and above "Restart"? I ask this 'cos I get the feeling there's something I'm not getting about what "sleep" means...

Once upon a time there was sleep, as in monitor off, then there was sleep where many components were put into low power mode, then there was deep sleep where most of the computer is actually off, even fans.

On my Quicksilver, I either use 'option + Apple Key + Eject' keyboard shortcut to sleep it or from the Apple menu 'Sleep'. This results in everything but the USB buss sleeping though even some USB devices will sleep too. Deep sleep parks the disks, spins 'em down. Now, undoubtedly something is open as any running programs, files, windows and whatnot are still the same as when you slept the machine. So I _could_ a problem. This being said I've never noticed any problem because of a power outage during sleep.

MT - Diagonally parked in a parallel universe.

101010

Message #10 - Posted 2004/04/23 - Simon Slavin

On 21/04/2004, Keeper of the Purple Twilight wrote in message <2fChc.64232$ec1.49577@okepread01>:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

You'll get the same kinds of problems: files partially overwritten or not created properly. It's not a good idea to do it for the same reason you don't turn off the power to a working Mac.

Disk Utility should clear up the problems most of the time, of course, but you're still running the risk of that once- in-a-blue-moon bad coincidence where you overwrite an important file.

Simon.

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Please tell me if it does weird things.

Message #11 - Posted 2004/04/24 - stan

In comp.sys.mac.system Keeper of the Purple Twilight wrote:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

In my case, a power failure hasn't harmed my G4 Cube in the slightest bit. In the building in which I live, we lose power about once every other month for some reason. Its been this way since I moved in about six years ago. Ideally, I would get a UPS, and you should probably get one too.

Message #12 - Posted 2004/04/28 - Clark Martin

Previously, Keeper of the Purple Twilight wrote:

If my iMac is in sleep mode, and the power goes out, does this cause any particular kind of harm to any files on the hard drive? (like it would if the computer was fully awake and the power got cut off)

For most things no. Some applications such as databases (like FileMaker Pro, FMP) leave their files open. However if it's in sleep then apps would likely have flushed any data to disk. FMP will complain that files weren't closed properly when this happens (or any other crash occurs with a file open). It then checks it and if it finds a problem will attempt to recover it. In my experience it rarely finds a problem, particularly when the computer shutdown during sleep. The nice thing about FMP is it does sense when a file wasn't closed properly and checks it. Most applications don't check their files and not only miss file corruption but allow it to increase.

Clark Martin
Redwood City, CA, USA Macintosh / Internet Consulting

"I'm a designated driver on the Information Super Highway"

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