What wears out in an HDD. Hybrid sleep

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For a friend with Win7.  

IIRC in Vista and 7, the default for a hard drive turning off was
never.   Never?  Even for people who leave their computer on 24/7?  
Doesn't it extend the life of the harddrive to turn it off when not in
use?   Or is it only the tone arm that breaks and the bearings the
platter rides on never break???  What wears out in an HDD?

When I was visiting him, I tried to set up his power options for him
but at the time I'd never heard of Hybrid Sleep.   I only had 30
minutes so I went home instead!    Wikip says "Sleep mode and
hibernation can be combined: The contents of RAM are copied to the
non-volatile storage and the computer enters sleep mode. This approach
combines the benefits of sleep mode and hibernation: "  But what I
read elsehwere was that the *data* areas of RAM were copied to the HDD
and it didnt' say how it knew where the data was kept.  My aunt Tillie
would hide data all over the house, in the cookie jar, the sofa
cushions, etc.  How do I know Hybrid Sleep finds all the data if it it
only tries to copy data??      

If one were to use plain old sleep on some computer, what data could
be lost in a power failure?   Is it only the most recent changes to a
file one is working on in a file composition window, like an email? Or
are there hidden non-easily recreatable files that also need to be

For example, if I change preferences and settings in most programs,
they are saved during full Hibernate or full Shutdown, but not at all
in simple sleep.  Are they saved in hybrid sleep?  

Also, full shutdown and full Hibernate obviate the need to run chkdsk
in case of a power failure.  If there is a power failure during hybrid
sleep, woudl chkdsk run on restart?   (Lets assume the user is away
from his desk so long that the UPS runs out of steam.)  

Thanks a lot  

Re: What wears out in an HDD. Hybrid sleep

Micky wrote:
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S3 Sleep - the session remains stored in RAM
          - open file changes could be lost on power fail
          - I don't know if the partition will be marked "dirty"
            on a power fail or not.

S4 Hibernate - the session is stored on disk
              - the next boot, reloads RAM contents from disk
              - unless the hiberfile was corrupted somehow,
                it should be relatively bulletproof

Hybrid sleep - the session remains stored in RAM
              - a duplicate copy is kept on disk (hiberfile)
              - on restart, if RAM preserved the session,
                the session continues very quickly from where
                it left off
              - on a power fail, the RAM content is lost,
                but on restart, the hiberfile is used to
                re-load the RAM. Your session is preserved
                and so on.

Hybrid sleep was intended to give you the advantages
of both. With the price being, that shutdown will be
a bit slower.

With regard to RAM contents:

1) You make a copy of RAM using physical addresses.
    You put the stuff back, where you got it from.
    Presumably the page tables (which map virtual to
    physical addresses) are also recorded. Nothing
    gets lost.

2) The OS keeps track of memory allocation. So it should
    have a good idea of "used" areas and "unused" areas.
    It can save time by not recording unused areas.
    (My RAMDisk gets lost, if I hibernate... That's for
    a RAMDisk that uses PAE space outside the licensed
    region. The OS pretends that area doesn't exist.)

3) There is no particular reason, that any RAM used as
    a system read file cache, would need to be preserved.
    That stuff could be flushed. The system file cache should
    really start over again, on the next startup.

4) In some cases, unused areas of RAM contain all-zeros,
    put there when something initialized the memory. I don't
    really know whether the BIOS does the first initialization,
    or the OS is doing it.

5) The hiberfile can use a lightweight compression scheme.
    This allows the hiberfile to be 48GB, on a 64GB RAM machine.
    So on modern OSes, the hiberfile is smaller than RAM, with
    the assumption of the designers being, the data will be
    "compressible enough" to always fit. By preparing a certain
    pathological case for the computer, I can violate that
    assumption, and prevent hibernation from working right.
    Normal usage should not do that.

6) You can tell from the relatively short shutdown cycle
    during hibernation, that not much is being written out.
    If you aren't using a lot of the RAM, the shutdown can
    be done in seconds. If you do the math (total_RAM divided
    by 100MB/sec for the disk), it should take forever to
    store the contents of all of your computer RAM. So obviously
    the scheme is pretty economical, only recording "chunks"
    that are needed, and ignoring the rest.

Only S3 Sleep would need a CHKDSK. And really, the only
things that should get lost, is file changes since
the last session. The NTFS journal should make cleanup
a snap to do.


Re: What wears out in an HDD. Hybrid sleep

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Well, lately I've just been walking away from the computer and letting
it do what it does when the time runs out, so it doesn't matter if
shutdown is slower.  I'm not there.  
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I'll grant you that unused areas don't need to be backed up.  

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I'll grant that.  

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I'll grant that if it's all zeroes, it probalby doesn't have to be
backed up.  

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Aha!  Just what I was worried about!

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Well, when I do actual hibernate, I didn't time it but I'd say it took
my 240GHz cpu 1 to 2 minutes to do 3 gigs.   (Does the cpu matter? I
don't know how new or how fast the HDDs were.)  But anyhow, 1 to 2

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I figure unless they  copy everything, they can't count on getting all
the data.  

Has anyone complained?  

I googled     hybrid sleep review      but i got a bunch of hits for
mattresses.     So I added -mattress.  

Then I got a bunch of hits for sleep labs and sleep studies, so I
added -sleep   but that didn't work!

Then I added    windows     but it said to keep the windows open if
you want a good night's sleep.   OK, JK, that worked.  

But all I find for reviews are discussions, not complaints.  

So I changed   review     to    bugs     but still no real complaints.
 Have you heard any?  

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One new question.  Say I have my email program set to send an email at
noon today, and now it's 5 in the morning and I'm going to sleep and
the computer will go to sleep in 20 minutes.  How can I keep it awake
until noon so it can send the email?    

I could use the Scheduler, but  the truth is I have trouble setting up
the Scheduler.   (I've made it work, but since then I've failed, but
please don't try to help me with this because I have no use for it
now. Just say if it's the best idea or not to send the email at noon.)
I could leave streaming audio or video playing, with the sound output
turned off, but even if a bad internet connection or something doesn't
stop that, I have the feeling that the computer can sleep and still
play streaming audio.  True??  

I could go into power options and change the very setting that makes
it sleep, but I"m trying to find some one-shot thing that's simpler
and wouldn't require unsetting later.  

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Re: What wears out in an HDD. Hybrid sleep

Micky wrote:

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In the past, one of the problems with the scheduler, was the
waking of the computer took time, and if your application
was expecting to do something instantly, the computer might
not be ready. So you may want to do something that sets
a WakeTimer, which wakes the computer five minutes before
the actual event you expect to service, and then set the
Sleep timer to ten minutes, so there is slack on either
side of the desired time. If the keyboard/mouse are inactive,
then maybe the Sleep policy cuts in, and puts the machine
back to sleep.

If a program contains its own notion of scheduling internally,
it should create its own Scheduler entries to wake itself
and perform the function correctly. Maybe Media Center
would do something like that, wake the machine when it is
time to record a program. And the user generally sets
the time, so the recording action starts about five minutes
before the program is about to begin, so nothing is lost.

With the Windows OS, the more modern the OS, the more of a
PITA it is to use the Scheduler. Now they have some
ugly piece of work "schtasks.exe" or similar, with a huge
set of command line options. And while I think options
are nice, I don't really want to spend half the day crafting
just the right command invocation for it.

In WinXP, you could use "at".

    at 15:03 "C:\Program Files\Media Center\mediacenter.exe" --someoption

That syntax makes it easy to set up, the user can concentrate
on the "junk for the payload". But if the program was clever,
it would work the WakeTimers itself, so you didn't have to
do that sort of gruntwork.

Generally, for a scheduled task, I recommend writing a batch file
(.bat). As you can embed a bit more clever stuff in the script,
to make sure things work right. For example

    sleep 300
    "C:\Program Files\Media Center\mediacenter.exe" --someoption

That would allow you to schedule something, it wakes the computer,
the script waits five minutes, then it executes the command on
the (now fully awake and ready to go) computer.

I don't do a lot of stuff with the Scheduler, so I don't
know all the tips and tricks. This is just a bit of stuff
from playing around one day.


Re: What wears out in an HDD. Hybrid sleep

On 1/4/2016 2:05 AM, Micky wrote:
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I don't fully understand your priorities.
I don't have a lot of experience with wake from sleep, but MediaCenter
can and does wake my machine from non-hybred sleep at
whatever time I set it to record something.  I expect there are apps
that can control that timing.  A real KLUDGE would be to just
program a recording when you want the machine awake, but it may
not let you do that without a tuner installed.

Depending on the bios, you may be
able to wake from OFF.  Wake on LAN is an example of that.

Sounds like you're willing to keep the machine running until noon.
What I do is to have two icons on my desktop.  One sets up for sleep.
The other sets up for nosleep.  When I don't want the system to sleep
during a download, I just click the nosleep icon.

Sleeper sets the balanced plan which is set up for sleep.
C:\Windows\System32\powercfg.exe -setactive  

Nosleep sets the high performance plan which is set for no sleeping.
C:\Windows\System32\powercfg.exe -setactive  

It's been a while since I did this, but I think it's all documented
in the powercfg manual.

If I just try to wake a sleeping system with a keystroke, it goes back
to sleep rather quickly.  I have to move the mouse to get the screen to
light up and stay awake until the sleep timer expires again.

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