
Why is there a screen that says “It is now safe to turn off your computer”? - ingve
https://blogs.msdn.microsoft.com/oldnewthing/20160419-00/?p=93315
======
Diederich
This might be alarming to some, but I have been hard-crashing all of my
personal Linux boxes (and some of the Linux boxes under my professional care)
for quite a few years.

That is, if a physical power button (often a toggle switch on the power
supply) is close, I'll toggle it off.

Most of the time, I'll hold the reset/power/whatever button down until the
device clicks off.

Linux and its filesystems have made this a (generally) safe thing to do for
many years. I started doing it after I read a lwn.net article, ages ago, about
how ext3's crash recovery path was discovered to be a bit faster than its
normal, clean mount path. If I recall, that happened because so much more of
the focus was put into that 'bad' path that it ended up more efficient than
the 'good' path.

Full disclosure: if I wish to do the crash thing immediately after a bunch of
relevant file writes, I will type 'sync' on one of my many terminals first. (:

~~~
ambrop7
You're placing a lot of trust in you presumably consumer-level disks. Even if
the filesystem is perfectly crash-tolerant under some specific model of disk
behavior, the disk could always behave outside of that model, especially upon
sudden loss of power.

Story: some time ago, I tried to hook up an SATA hard disk into a desktop PC
which had an SSD connected, while the machine was running. When I did so, I
got errors in dmesg about the SSD failing and being reset automatically. I
rebooted and grub took ~30s to load the kernel then the boot hanged in the
middle. Luckily after some power cycling the issue was gone but I honestly
taught I lost the SSD. Apparently disks don't like losing power. Possibly this
was even worse because it was just a temporary voltage drop (the disks were
connected to the same supply cable).

~~~
javajosh
Is SATA designed to allow hot plugin of a hard drive? That would surprise me.

~~~
ambrop7
As far as I know, it is an optional feature that both the controller and the
drive have to support, to use reliably.

~~~
dogma1138
And it then needs to be explicitly requested which usually means bypassing the
cache to avoid any delayed writes.

But even then hotswap was never meant to ensure data consistency it just
allows the controller to reinitialize new disks without a full reset.

------
tobr
I found this mildly interesting: the "screenshots" in this article are made
out of HTML elements.

~~~
digi_owl
And using a Windows only font for the "moon and stars" dialog. At least the
supposed moon comes up as a "missing character" in Firefox on Linux.

~~~
wlesieutre
Unicode U+1F319 "crescent moon", it exists on OS X but it significantly
different from the Windows version (yellow and orange shading vs solid white
silhouette).

Since the visual appearance matters here more than being searchable by "",
drawing the shape in CSS would be more consistent:
[http://aamirshahzad.net/moon-with-css3/](http://aamirshahzad.net/moon-with-
css3/)

EDIT: Pretend there's a moon in those quotes. HN strips some Unicode
characters, including that one.

------
woliveirajr
Ahh, those transitions from the days where you could just turn off you DOS,
until the computer could "turn off" by itself (I know, not that hard off, just
a soft button off)

~~~
digi_owl
We seem to be heading back towards those days.

The property that made this possible was that DOS had little "state" to save
before going bye bye.

And these days you get much the same with ChromeOS.

Heck, was there not someone in the -sec community arguing that state was to be
considered bad?

~~~
JBiserkov
There was a very funny video where the main character's Chrome book gets
destroyed every few minutes and a new one is delivered and he just keeps on
working.

~~~
digi_owl
[https://www.youtube.com/watch?v=lm-
Vnx58UYo](https://www.youtube.com/watch?v=lm-Vnx58UYo)

Seeing that original browser only UI makes me nostalgic.

------
Someone
Reminds me of
[http://www.guidebookgallery.org/pics/gui/startupshutdown/shu...](http://www.guidebookgallery.org/pics/gui/startupshutdown/shutdowncomplete/macos42.png),
and the time I patched the Mac OS System Error Handler.

The patch I made tried to speak the text of the error message. It turned out
that worked fine, if you opened a SpeechChannel before the crash (we had one
open, anyways, and patched a zillion calls, so it worked first time round) and
you were lucky (the System Error Handler was the part of the OS that was
designed to show system errors, making as few assumptions as possible on what
part of the OS was still functional; without memory protection, a crash could,
for instance, mean that the memory manager data structures got corrupted, or
that font data got overwritten, so there was no way to guarantee that the
MacinTalk voice data wasn't corrupted)

The day our beta tester excitedly reported that the test Mac SE (one of the
few Macs at the time that couldn't switch itself off in software) spoke the
text of that alert when you selected "Shut Down" in the Finder, I learnt that
that alert was a system error alert.

([http://www.guidebookgallery.org/index](http://www.guidebookgallery.org/index)
is a nice site for the nostalgic, by the way)

------
ArkyBeagle
Because of the ancient hell that is FAT32.

And yet you own at least one device which is FAT32 to this day. You nearly
have no choice.

Two class-action lawsuits I'd like to see: Open NTFS. ext4 support on all
versions of Windows.

~~~
justinlardinois
What would be the grounds for a lawsuit about either of those things?

~~~
digi_owl
Microsoft, being the single biggest supplier of desktop operating systems, are
holding back interoperability by not supporting file systems that are freely
implementable on other platforms.

Supposedly one reason Google do not have SD slots on their Nexus devices is to
avoid getting into a patent quarrel with Microsoft regarding FAT.

~~~
justinlardinois
I can't imagine even the best lawyers finding grounds to sue someone to force
them to support a technology.

And as for patents...again, the way to deal with that would be to wait for
Microsoft to sue for patent infringement.

Lawsuits aren't some magical tool you can use to shape reality in your image.

~~~
ArkyBeagle
Oh, I understand completely. But just wait 'til you have to face a borked
FAT32 file system in a customer system. It's unpleasant.

------
acqq
Ah, bad old days, when you command the computer to shut down and it cleans a
little and stays on, suggesting to restart it, what else would you want to do
anyway?

I remember the orange bitmapped letters of 95, that color and the jagged
letters stayed in my mind.

I've used Windows NT, various versions, but somehow suppressed the memory of
the final screen. Anybody knows which version(s) of Windows NT offered
"Restart" after the shutdown?

~~~
mrpippy
[http://www.guidebookgallery.org/screenshots/shutdowncomplete](http://www.guidebookgallery.org/screenshots/shutdowncomplete)

NT 3 and 4 did, and you always saw them since it didn't support soft power-off
(although I vaguely remember there was a registry key to enable it but didn't
work for me).

Win2000 removed the button (and looks like it was just showing a bitmap,
rather than keeping the window system running)

------
forinti
It wouldn't have hurt to keep the Restart button, just like RISCOS. The
problem was the message, not the button.

[http://www.guidebookgallery.org/pics/gui/startupshutdown/shu...](http://www.guidebookgallery.org/pics/gui/startupshutdown/shutdowncomplete/riscos37.png)

~~~
chocolatebunny
You assume people don't blindly click on things until the desired affect takes
place.

My brother went to a website that had a link to a pdf he wanted to read but
adjacent to that link was an "install acrobat reader" button that looked more
inviting. He kept on clicking and installing acrobat reader assuming that it
would eventually go to the link he wanted. He eventually complained to me that
his computer didn't have acrobat reader and no matter how many times he tried
he couldn't install it. It was only after I went to the website that I
realized what the problem is.

------
WatchDog
Is it possible to have a modern desktop computer that doesn't support power
management? Do modern windows operating systems still have the safe to
shutdown dialog for that scenario?

------
stuaxo
Yup. The thing to do was to have an autoexec.bat that had

win.com mode co80

that way "shut down" windows would put you back at the dos prompt (if not you
could just type "mode co80" and start using dos)

