POV-Ray : Newsgroups : povray.off-topic : Damn! Server Time
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From: Darren New
Subject: Re: Damn!
Date: 25 Jan 2009 18:01:23
Message: <497cef43$1@news.povray.org>
Warp wrote:
>   Including things like cellphones, digital cameras, etc?

Probably more than exFAT, yah. At least the specs are published. :-)  I bet 
an Android phone would work with NTFS better than exFAT.

Thinking on it, tho, NTFS has all kinds of features that something like a 
camera wouldn't want, like ACLs, ownership of files, compression, 
encryption, etc etc etc.  A good reason not to use it, I guess.

-- 
   Darren New, San Diego CA, USA (PST)
   "Ouch ouch ouch!"
   "What's wrong? Noodles too hot?"
   "No, I have Chopstick Tunnel Syndrome."


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From: clipka
Subject: Re: Damn!
Date: 25 Jan 2009 21:40:01
Message: <web.497d2270f0e84c4063cb5da50@news.povray.org>
Darren New <dne### [at] sanrrcom> wrote:
> Thinking on it, tho, NTFS has all kinds of features that something like a
> camera wouldn't want, like ACLs, ownership of files, compression,
> encryption, etc etc etc.  A good reason not to use it, I guess.

There are more good reasons to use FAT:

- NTFS is optimized for fixed media; FAT was *designed* with removable media in
mind. (Note that a file system is more than the data structures on disk; it
also includes some protocol of how to update them.)

- Flash media internally typically use their own specialized file system anyway,
to perform load balancing and bad block management. FAT is easy enough to
implement a mapping to the flash file system in reasonably simple hardware.


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From: Darren New
Subject: Re: Damn!
Date: 25 Jan 2009 22:45:14
Message: <497d31ca$1@news.povray.org>
clipka wrote:
> - NTFS is optimized for fixed media; FAT was *designed* with removable media in
> mind. (Note that a file system is more than the data structures on disk; it
> also includes some protocol of how to update them.)

Right. While it's true that FAT was designed with removable media in mind, 
it wasn't designed with removable media being randomly removed in mind. :-) 
It's quite easy to corrupt FAT by turning off the power or unplugging the 
media in the middle of an operation.

When's the last time you saw Windows run chkdsk on NTFS when you boot, 
compared to running scandisk under Win98 when it crashes?

Besides that, what's your thought on why FAT would be better for removable 
media?

> - Flash media internally typically use their own specialized file system anyway,
> to perform load balancing and bad block management. FAT is easy enough to
> implement a mapping to the flash file system in reasonably simple hardware.

I'll take your word on that one. :-)

-- 
   Darren New, San Diego CA, USA (PST)
   "Ouch ouch ouch!"
   "What's wrong? Noodles too hot?"
   "No, I have Chopstick Tunnel Syndrome."


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From: Eero Ahonen
Subject: Re: Damn!
Date: 29 Jan 2009 12:44:51
Message: <4981eb13@news.povray.org>
Darren New wrote:
> 
> Right. While it's true that FAT was designed with removable media in
> mind, it wasn't designed with removable media being randomly removed in
> mind. :-) It's quite easy to corrupt FAT by turning off the power or
> unplugging the media in the middle of an operation.

Nor over 1MB-sized media (speaking about original FAT).

> When's the last time you saw Windows run chkdsk on NTFS when you boot,

Every time I boot my work-laptop (it doesn't turn the dirty bit off,
which is kind of annoying).

> compared to running scandisk under Win98 when it crashes?

Umm... not THAT often (I don't reboot my laptop twice a day;).


Btw, that mentioned work-laptop still steals focus too often, even
though I did turn focus-stealing off from TweakUI.

-Aero


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From: Darren New
Subject: Re: Damn!
Date: 29 Jan 2009 13:01:48
Message: <4981ef0c$1@news.povray.org>
Eero Ahonen wrote:
> Nor over 1MB-sized media (speaking about original FAT).

Well, yeah, but come on, FAT-16 is like what, 15 years old?

>> When's the last time you saw Windows run chkdsk on NTFS when you boot,
> 
> Every time I boot my work-laptop (it doesn't turn the dirty bit off,
> which is kind of annoying).

That's odd. Did you run it manually? I've never had NTFS tell me it's 
corrupt, even when I've lost power during a defrag or something.

> Btw, that mentioned work-laptop still steals focus too often, even
> though I did turn focus-stealing off from TweakUI.

Yeah. I think Vista ignores that stuff to a large extent. The worst is when 
you get modal dialog boxes that manage to come up behind the main window, 
with nothing in the taskbar and the main window won't let you move it. I 
haven't quite figured out how to fix that one.  (Except maybe locking and 
unlocking the screen?)

-- 
   Darren New, San Diego CA, USA (PST)
   "Ouch ouch ouch!"
   "What's wrong? Noodles too hot?"
   "No, I have Chopstick Tunnel Syndrome."


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From: Eero Ahonen
Subject: Re: Damn!
Date: 29 Jan 2009 13:44:42
Message: <4981f91a@news.povray.org>
Darren New wrote:
> Eero Ahonen wrote:
>> Nor over 1MB-sized media (speaking about original FAT).
> 
> Well, yeah, but come on, FAT-16 is like what, 15 years old?
>

Yep, so it's clear that todays gigabytes-sized medias weren't around
back then. But it still means that there are visible flaws when running
big medias with such filesystem - FAT32 fixed the problem with huge
clusters, but even FAT32 was pretty unstable when run with Win98 on over
20-gig partitions (dunno why, for some reason 20+GB seemed to crash more
easily than under 20GB partitions). Still today FAT - or at least it's
Windows implementations - suck at least on some level when you have
enough files.

FAT was designed for removable media. It wasn't designed especially for
flash drives nor for huge medias. It's being helped to breath for over
10 years now.

> That's odd. Did you run it manually? 

Nope.

> I've never had NTFS tell me it's
> corrupt, even when I've lost power during a defrag or something.

That's a known bug, I've hit it some time earlier also - there's no
failure in filesystem, but Windows thinks it should be checked, like
after unclean poweroff. There's a simple fix somewhere, I've just been
too lazy to find it again :).

>> Btw, that mentioned work-laptop still steals focus too often, even
>> though I did turn focus-stealing off from TweakUI.
> 
> Yeah. I think Vista ignores that stuff to a large extent. 

...except that I'm running XP on that particular laptop.

> The worst is
> when you get modal dialog boxes that manage to come up behind the main
> window, with nothing in the taskbar and the main window won't let you
> move it. I haven't quite figured out how to fix that one.  (Except maybe
> locking and unlocking the screen?)
> 

I think I've been lucky, since I haven't got such thing. I think one of
the nastiest things are that when antivirus updates the engine, it might
ask for reboot - just finishing a line on some script and press enter...
And there you go.

-Aero


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From: Darren New
Subject: Re: Damn!
Date: 29 Jan 2009 17:00:01
Message: <498226e1$1@news.povray.org>
Eero Ahonen wrote:
> easily than under 20GB partitions). Still today FAT - or at least it's
> Windows implementations - suck at least on some level when you have
> enough files.

No, that's true. Big directories are searched linearly, and the free space 
needs to get scanned to find blocks. So if your disk is big and close to 
full, allocating a block can take a lot of I/O, or require you to hold the 
entire map in memory.

Fat-64 (aka exFAT) seems to be designed to address just these problems.

>> That's odd. Did you run it manually? 
> Nope.

I suggest maybe "chkdsk /f" at the command line, schedule a scan, and 
reboot? :-)

> That's a known bug, I've hit it some time earlier also - there's no
> failure in filesystem, but Windows thinks it should be checked, like
> after unclean poweroff. There's a simple fix somewhere, I've just been
> too lazy to find it again :).

Oh, I remember that. Some of the disk drives didn't actually flush the last 
blocks written when you power them off. The patch just delays the actual 
remove-power-from-drive for a second or two so the drive will flush out the 
memory. But that's an ooooold bug.

> ...except that I'm running XP on that particular laptop.

Weird.

> I think I've been lucky, since I haven't got such thing. I think one of
> the nastiest things are that when antivirus updates the engine, it might
> ask for reboot - just finishing a line on some script and press enter...
> And there you go.

Yeah. That's what the focus stealing prevention is supposed to prevent. :-)

-- 
   Darren New, San Diego CA, USA (PST)
   "Ouch ouch ouch!"
   "What's wrong? Noodles too hot?"
   "No, I have Chopstick Tunnel Syndrome."


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From: Eero Ahonen
Subject: Re: Damn!
Date: 31 Jan 2009 02:36:31
Message: <4983ff7f$1@news.povray.org>
Darren New wrote:
> 
> No, that's true. Big directories are searched linearly, and the free
> space needs to get scanned to find blocks. So if your disk is big and
> close to full, allocating a block can take a lot of I/O, or require you
> to hold the entire map in memory.
> 
> Fat-64 (aka exFAT) seems to be designed to address just these problems.

Maybe FAT some day will be designed for huge medias then :). I hope and
think they don't end up with just pumping up the address space (which
AFAIK pretty much is what they did with FAT-32).

> I suggest maybe "chkdsk /f" at the command line, schedule a scan, and
> reboot? :-)

That schedules the check for next reboot, and it was doing that already
;). Anyway, it crashed couple a days ago, which seems to have fixed the
problem :D.

-Aero


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From: Darren New
Subject: Re: Damn!
Date: 31 Jan 2009 13:15:20
Message: <49849538$1@news.povray.org>
Eero Ahonen wrote:
> Maybe FAT some day will be designed for huge medias then :). I hope and
> think they don't end up with just pumping up the address space (which
> AFAIK pretty much is what they did with FAT-32).

They added a bitmap for free space lists, ACLs (which would seem to imply 
ownership), different timestamps and different limits on various things like 
directory size, some transaction safety (which would seem to imply 
journaling of some sort), and so on.

I.e., all the good stuff of NTFS, shoehorned into FAT.  Bleh. The whole 
point of FAT was that it was trivial to understand and implement. :-)

> That schedules the check for next reboot, and it was doing that already
> ;). 

The dirty bit is stored in a different place than the scheduled chkdsk, so I 
was guessing it might ignore and clear the dirty bit if you invoked it manually.

> Anyway, it crashed couple a days ago, which seems to have fixed the
> problem :D.

You mean it *actually* set the dirty bit. :-)

-- 
   Darren New, San Diego CA, USA (PST)
   "Ouch ouch ouch!"
   "What's wrong? Noodles too hot?"
   "No, I have Chopstick Tunnel Syndrome."


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From: Eero Ahonen
Subject: Re: Damn!
Date: 31 Jan 2009 14:33:10
Message: <4984a776@news.povray.org>
Darren New wrote:
> They added a bitmap for free space lists, ACLs (which would seem to
> imply ownership), different timestamps and different limits on various
> things like directory size, some transaction safety (which would seem to
> imply journaling of some sort), and so on.

Nice, but...

> I.e., all the good stuff of NTFS, shoehorned into FAT.  Bleh. The whole
> point of FAT was that it was trivial to understand and implement. :-)

...exactly (why oh why would they leave out the alternate data streams
:p). OTOH it could be licencial politics from MS, still keeping NTFS as
theier own child and not let it out.

> The dirty bit is stored in a different place than the scheduled chkdsk,
> so I was guessing it might ignore and clear the dirty bit if you invoked
> it manually.

Ah.

> You mean it *actually* set the dirty bit. :-)

Yes, and unset it also. It now boots up nicely again. :-)


-Aero


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