# Hard Restart / Soft Restart - is there a difference?



## Morf (Nov 18, 2010)

OK, I've put this discussion here in TT&T I think it relates to the answers that we give to people who ask questions on the forums, especially on TT&T. If the mods think it should be elsewhere (eg forum decorum) please feel free to move it.

Let me set the context for this discussion:

"Hard restart" - hold the power switch for 30 seconds or so.
"Soft restart" - Home, Menu, Settings, Menu, Restart.

Now, my belief is that these two both do the same thing: ie they restart your Kindle. The soft restart is like doing a "restart" from the start menu on your PC - ie you do it from the menus - whereas the hard restart is like turning the power to your PC off and back on again.

By that logic, the soft restart is maybe safer that the hard restart, but the end result of both is the same.

Therefore, I always advise people to do a soft restart if they can, and only do a hard restart if they cannot do a soft restart.

Now I've noticed that some people on here - Ann in particular - believe differently, they believe that the two restarts are different, and that the hard restart may be more effective than a soft restart. See for example http://www.kboards.com/index.php/topic,88172.0.html where Ann says:



Ann in Arlington said:


> Soft restart: menu/settings/menu/restart.
> 
> If it's still happening, hard restart: slide and hold the switch for 30-40 seconds. Let it reboot itself.
> 
> If it's still happening, contact Kindle Support...


Now let me be very clear here - I'm not arguing with Ann - I wouldn't dare!  - but I feel that we are giving people conflicting advice here and I'd like us to try to be consistent.

So, what do people think?

Is a soft restart "safer" than a hard restart?

Does a hard restart do any more than a soft restart?

Does it really, cosmically speaking, matter?


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## Ann in Arlington (Oct 27, 2008)

To clarify, it's not a question of 'safety' for me.  I agree that they probably do substantially the same thing.

My feeling is that if you can do it via the software, that's easier.  It's also less wear and tear on the power switch -- though that's probably a consideration not really worth mentioning. . . except people have reported 'looseness' and 'stickiness' with the switch -- not necessarily related to restarts -- and it is a mechanical thing.

BUT. . .sometimes the device is frozen and you have no choice but to use the hard restart.  It's a good thing there is that option! 

Or sometimes the problem persists after a soft restart.  People have reported that the HARD restart has resolved problems that were not fixed via a soft restart.  I can't explain why. But it makes sense to me that before calling KS it's a good idea to have tried both.  'Cause they'll probably ask you to anyway and you can tell 'em you did that already.


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## Morf (Nov 18, 2010)

Ann in Arlington said:


> To clarify, it's not a question of 'safety' for me. I agree that they probably do substantially the same thing.


"Safety" was my comment, I know with PCs it's a lot safer to do a soft restart (ie from the start menu) than to do a hard restart (with a reset switch or the power switch). The soft restart is a controlled restart which gives the OS a chance to close down cleanly.

So I suppose the first question is, does a menu restart do a controlled restart, and does this matter to the Kindle?



Ann in Arlington said:


> People have reported that the HARD restart has resolved problems that were not fixed via a soft restart. I can't explain why.


...and that's what intrigues me - can you remember any specific cases? On a PC, a hard restart will not fix anything a soft restart won't. Powering the PC completely off and back on can make a difference, but I don't think the Kindle hard restart is doing that.

Or is it? Maybe the power switch restart is killing power to the Kindle completely for a moment, which might possibly have more of an effect than a restart would.

I entirely agree with the idea of doing both anyway to keep CS happy, I'd just love to know whether there really is a difference.

I can't help it, I'm a techie (working for a global IT company) and we always want answers in black and white, not shades of grey!


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## Linjeakel (Mar 17, 2010)

Morf said:


> Or is it? Maybe the power switch restart is killing power to the Kindle completely for a moment, which might possibly have more of an effect than a restart would.


I always assumed a hard restart was when you switched the Kindle completely off and then had to slide the switch again to start it - whether it be straight away, or minutes or hours later. In that way it would be equal to a 'shut down' on a PC, rather than a 'restart' - something which does in some cases make a difference. I have no idea _why_ of course, but I just assumed it worked the same way on a Kindle.

I think the confusion arises because no-one seems to know exactly how long to hold the slider switch before it works. On both my K3 and DXG a five second hold will clear the screen - no sleep picture etc - and gives the impression it's completely off. But slide the switch again and it comes straight back on to the home screen. Hold the switch for about 20 seconds or so and although it appears exactly the same - i.e. it goes off to a blank screen after about 5 seconds and stays like it - when I then slide the switch again it does a proper restart - boy under the tree and progress bar etc. At least if you tell people to use the menu restart you know it has actually restarted and not just gone to sleep.

Incidentally, no matter how long I hold the switch across, it never restarts until I let go and slide the switch again, which is not what it tells you will happen in the official Amazon instructions.


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## Ann in Arlington (Oct 27, 2008)

Linjeakel said:


> Incidentally, no matter how long I hold the switch across, it never restarts until I let go and slide the switch again, which is not what it tells you will happen in the official Amazon instructions.


I've noticed that too. . . I saw something somewhere about watching for the light to blink but don't recall where. . . . .


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## NiLuJe (Jun 23, 2010)

I'd go with the soft restart if possible, and avoid the hard restart unless there's no other way, because, yes, it's dirty, and yes, there's a (tiny, tiny) chance it'll mess the filesystem up.

It's not uncommon to see an ext3 journal replay in the logs after a dirty reboot. (It's ext3, it's journaled, it's pretty resilient, but still, I'd avoid playing with fire ;p).


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## Ann in Arlington (Oct 27, 2008)

Are there other words you could use to explain that, NiluJe?  Sorry. . . I'm not really fluent in coding and don't understand "ext3 journal replay" 

thanks.


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## Morf (Nov 18, 2010)

Linjeakel said:


> I always assumed a hard restart was when you switched the Kindle completely off and then had to slide the switch again to start it


Now, this gets more interesting. Personally, I don't believe the "off" state of the Kindle is anything of the sort - I suspect it's only there to fool flight attendants who think "blank screen = turned off". I think the only real difference between screensaver sleep and blank screen "off" is that the screen is blank.

On my K3, as soon as you slide the switch the green light comes on. If you release at that time, it goes into screensaver sleep.
If you hold for about 5 secs, the light flashes (off-on-off-on-off) and then stays off. If you release then, it *still* goes into screensaver sleep. If you hold it for a second or so longer, the screen goes blank, and if you release it then it is "off" (but still restarts instantly).
If you hold and keep holding, the screen blanks, but then there is no visual cue (light or screen) that it is going to restart, you just seem to have to hold it for a long time, then release it. Then, as you say, you need to switch it back on to cause the restart.

I definitely feel that many people only hold the switch until the screen blanks, and think this is a restart, which it clearly isn't.



NiLuJe said:


> I'd go with the soft restart if possible, and avoid the hard restart unless there's no other way, because, yes, it's dirty, and yes, there's a (tiny, tiny) chance it'll mess the filesystem up.
> 
> It's not uncommon to see an ext3 journal replay in the logs after a dirty reboot. (It's ext3, it's journaled, it's pretty resilient, but still, I'd avoid playing with fire ;p).


...and this makes it even more interesting. If a hard restart is a dirty restart, then clearly a soft restart is safer. NiLuJe, you clearly know more about the insides than most of us, any feel for whether a hard restart could fix problems that a soft restart doesn't?



Ann in Arlington said:


> Are there other words you could use to explain that, NiluJe? Sorry. . . I'm not really fluent in coding and don't understand "ext3 journal replay"
> 
> thanks.


File system - the way in which files are written to a disk. On Windows you would know of FAT, FAT32 and NTFS as file systems, NTFS is the best of those. 
ext3 - one of the best file systems used by Linux. I'm not going to start a discussion about whether ext3 is better than NTFS 
journal - the computer can keep a record of changes it's making to the file system, so if something goes wrong it knows about it - eg if the machine is turned off suddenly.
replay - the mechanism used after an unexpected restart to check which changes did and didn't happen, and redo the ones that didn't.

So hard restarts are not clean, the Kindle has a good go at recovering from them, but it _may_ go wrong!


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## NiLuJe (Jun 23, 2010)

I can't remember how long you have to flip the switch, but AFAIR, there is a complete 'off' state (ie. shutdown/halt), but I do remember that the timing of it is pretty tricky between standby/restart/off . (That's simple enough to check, if you get a blank screen, and the next time you flip the switch, you see the 'Your Kindle is starting up' screen, [ie. not the progress bar], then if was truly off).

As for the 'dirty' restart, there's a somewhat obscure (at least for us common mortal beings ) boot flag involved in a soft restart (that's also relevant to modern desktop/laptop computers) that the OS can set, and which dictates whether a restart will be 'cold' or 'warm'. I'm pretty vague on the details, but the default for a modern OS (Kindle included) is to do a warm restart, that's somewhat faster because it doesn't reset the state of some very low-level stuff (and also, at least on x86 systems with a BIOS, doesn't trigger the memory checks, which can be time consuming on large memory systems) [I may be talking out of my bottom here, it's pretty obscure/low level stuff that I never really learned that much about]. And while you can do a cold soft restart, a shutdown or hard reboot will have the same effect (ie. cold instead of warm). That may explain the discrepancies (or not ).

As for the journaling stuff, basically, on Windows, you would see the good old 'fsck' screen before the Windows boot (or I guess since Vista more likely the forced stop at the bootloader stage to ask you if you want to start windows in safe-mode) if the system found the FS in a crappy state, and on NTFS, that may involve playing with the journal to recover stuff (it's basically literally a journal, the system log what's happened to which file and when, and it's used for recovery purposes when the FS gets conked on the head somehow, sudden power losses/crashes being the main causes for that to happen ;p).

And on the Kindle, the hard reset is indeed pretty harsh, since it disconnects the battery for a short period of time (ie. it's as if you were to suddenly pull the plug on your desktop computer/suffer a power outage).


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## Morf (Nov 18, 2010)

Thanks NiLuJe, fascinating stuff! 



NiLuJe said:


> I can't remember how long you have to flip the switch, but AFAIR, there is a complete 'off' state (ie. shutdown/halt), but I do remember that the timing of it is pretty tricky between standby/restart/off . (That's simple enough to check, if you get a blank screen, and the next time you flip the switch, you see the 'Your Kindle is starting up' screen, [ie. not the progress bar], then if was truly off).


That sounds like the state I'm seeing if I hold the switch for long enough, and indeed the timing is not obvious 

There is clearly a "screensaver" state, a "visually off" state (which I still think are not significantly different), and a "powered down" state (which is what the Kindle is in after the long switch hold until you turn it back on.



NiLuJe said:


> As for the 'dirty' restart, there's a somewhat obscure (at least for us common mortal beings ) boot flag involved in a soft restart (that's also relevant to modern desktop/laptop computers) that the OS can set, and which dictates whether a restart will be 'cold' or 'warm'. I'm pretty vague on the details, but the default for a modern OS (Kindle included) is to do a warm restart, that's somewhat faster because it doesn't reset the state of some very low-level stuff (and also, at least on x86 systems with a BIOS, doesn't trigger the memory checks, which can be time consuming on large memory systems) [I may be talking out of my bottom here, it's pretty obscure/low level stuff that I never really learned that much about]. And while you can do a cold soft restart, a shutdown or hard reboot will have the same effect (ie. cold instead of warm). That may explain the discrepancies (or not ).


Interesting, I wasn't aware of this "warm restart" stuff in modern kit (I'm an old-school guy) but it does make sense.



NiLuJe said:


> And on the Kindle, the hard reset is indeed pretty harsh, since it disconnects the battery for a short period of time (ie. it's as if you were to suddenly pull the plug on your desktop computer/suffer a power outage).


Ouch! Harsh indeed.


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## Morf (Nov 18, 2010)

OK, summary of what we've seen so far:

A soft restart using the menus is a *lot* kinder to your Kindle than a hard restart. Therefore we should be recommending this whenever possible. Only use a hard restart if the Kindle is completely unresponsive.

A hard restart is a "deeper" restart than a soft restart, so if a soft restart does not fix the problem, you should then try a hard restart as a last resort just in case that helps, then phone Kindle CS.

There are three "off" states - screensaver, blank screen (which we think is the same but with the screen blanked) and totally off which will cause the "restarting" messages at power up. For normal use, screensaver is all that is needed.

Linjeakel, unless anybody has anything more to add please could you update the FAQs with this information?

Thanks to everybody who's contributed, special thanks to NiLuJe for the insider knowledge!


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## Ann in Arlington (Oct 27, 2008)

It might be good to note that if the battery is really low, it's probably best to fully charge the thing before trying any of this. . . .or, at least, it seems so to me.  I know that when, for instance, my phone is nearly dead, it doesn't want to do anything but turn off and stay off.  I don't blame it, really, so I plug it in and let it have a good charge up.


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## Linjeakel (Mar 17, 2010)

I've updated the 'Help My Kindle is Frozen!' FAQ with this info and put a link back to this discussion for anyone who wants more details.

Morf, would you check it out and see if I've explained it properly, or if you think I need to add anything? Thanks.


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## NiLuJe (Jun 23, 2010)

There's indeed a battery level check, it'll fail to boot completely if the battery is too low (not sure what's the feedback on screen, but the system is in place) .


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## Betsy the Quilter (Oct 27, 2008)

I do so love it when y'all talk geek...

Betsy


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## Morf (Nov 18, 2010)

Linjeakel said:


> I've updated the 'Help My Kindle is Frozen!' FAQ with this info and put a link back to this discussion for anyone who wants more details.
> 
> Morf, would you check it out and see if I've explained it properly, or if you think I need to add anything? Thanks.


Looks fine to me Linjeakel, thanks!



Betsy the Quilter said:


> I do so love it when y'all talk geek...
> 
> Betsy


You can't keep a good geek down!


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