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There are so many - what do you use for a freeware duplicate file finder on Windows?

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Arlen Holder

unread,
Aug 6, 2018, 5:06:04 PM8/6/18
to
Jesus...There are so many - what do you use for a freeware duplicate file
finder on Windows?

Googling, I find so many it's not funny...where you know there's a problem
when no two articles even have agreement on the top few.

First I tried the canonical duplicate file remover from Microsoft...
Microsoft Duplicate File Remover
<https://www.microsoft.com/en-us/p/duplicate-file-remover/9nblggh4sqnp>

But it was too much GUI and too little customization.
<http://www.bild.me/bild.php?file=9081255duplicatefileremover.jpg>

Then I searched for better duplicate file removers, and was aghast that
there is very little consensus among the "reviews" (many of which, I know,
are simply shills).

The Best Duplicate File Finder for Windows
* dupeGuru <https://dupeguru.voltaicideas.net/>
* Ccleaner <https://www.ccleaner.com/ccleaner>
<https://lifehacker.com/the-best-duplicate-file-finder-for-windows-1696492476>

What Is the Best Duplicate File Finder?
<https://www.easyduplicatefinder.com/best-duplicate-file-finder.html>

How to Find and Remove Duplicate Files on Windows
<https://www.howtogeek.com/200962/how-to-find-and-remove-duplicate-files-on-windows/>

5 Best Free Duplicate File Finder Software for Windows
<https://www.cisdem.com/resource/best-free-duplicate-file-finder-for-windows.html>

5 Best Free Duplicate File Finder and Remover
<http://perfectgeeks.com/free-duplicate-file-finder-remover/>
<https://www.top5freeware.com/duplicate-file-finder>
* Auslogics Duplicate File Finder <https://softfamous.com/auslogics-duplicate-file-finder/>
* AllDup <https://softfamous.com/alldup/>
* CloneSpy <http://www.filesriver.com/app/117/clonespy>
* Fast Duplicate File Finder <http://www.filesriver.com/app/118/mindgems-fast-duplicate-file-finder>
* Anti-Twin <http://www.filesriver.com/app/119/anti-twin>

26 Best Free Duplicate File Finders
<https://listoffreeware.com/list-of-best-free-duplicate-file-finder/>

What do you use for a freeware duplicate file finder on Windows?

Shadow

unread,
Aug 6, 2018, 5:14:13 PM8/6/18
to
I use an old version of Digital Volcano Duplicate Cleaner

https://www.digitalvolcano.co.uk/duplicatecleaner.html

Have not tried more recent offerings.
[]'s


--
Don't be evil - Google 2004
We have a new policy - Google 2012

nospam

unread,
Aug 6, 2018, 5:24:11 PM8/6/18
to
In article <pkad7o$rdl$1...@news.mixmin.net>, Arlen Holder
<arlen...@nospam.net> wrote:

> Jesus...There are so many - what do you use for a freeware duplicate file
> finder on Windows?

how is it that someone who repeatedly brags how well organized his file
system is ends up with duplicate files?

certainly you should know where they are, without any additional apps.

Sjouke Burry

unread,
Aug 6, 2018, 5:53:11 PM8/6/18
to
On 6-8-2018 23:06, Arlen Holder wrote:
> Jesus...There are so many - what do you use for a freeware duplicate file
> finder on Windows?
>

DoubleKiller 1.6.2.82 Portable :: Downloads / Misc :: winPenPack ...

Shadow

unread,
Aug 6, 2018, 7:41:56 PM8/6/18
to
On Mon, 06 Aug 2018 17:24:08 -0400, nospam <nos...@nospam.invalid>
wrote:
I use a duplicate finder to check that the ones I have backed
up to DVD are identical to the ones on disk. Good duplicate finders
use hashes and checksums.

Arlen Holder

unread,
Aug 7, 2018, 12:08:29 AM8/7/18
to
On 6 Aug 2018 16:41:21 GMT, Shadow wrote:

> I use a duplicate finder to check that the ones I have backed
> up to DVD are identical to the ones on disk. Good duplicate finders
> use hashes and checksums.

You need to ignore that troll "nospam" as he has never posted with any
helpful intent, and where there are entire threads about his mental status.
What are the common well-verified psychological traits of the Apple Apologists?
<https://groups.google.com/forum/#!topic/misc.phone.mobile.iphone/18ARDsEOPzM>

These Apple Apologists apparently hate that every other common consumer
operating system is far more functional than iOS is, that they simply
attack anyone they can who points out facts as they exist.

His entire belief system is based on imaginary fabrications of
functionality.

Anyway, to answer the question of why, in this case, I have two desktops
with three long-standing operating systems on each, which is well known in
the Windows 10 newsgroup, where I'm seeking to find duplicate files.

I think I will use your suggested Digital Volcano Duplicate Cleaner
<https://www.digitalvolcano.co.uk/duplicatecleaner.html>
Where I did try the canonical Microsoft duplicate cleaner, but didn't like
the lack of controls.

Thanks for being purposefully helpful by suggesting Digital Volcano
Duplicate Cleaner!
<https://www.digitalvolcano.co.uk/download/DuplicateCleanerFree4_setup.exe>

Apparently it's also on the "Microsoft Store" (if anyone actually uses it):
<https://www.microsoft.com/en-us/p/duplicate-cleaner-free/9nblggh4rrr3?rtc=1>

Thanks for being purposefully helpful (unlike that worthless troll nospam).

Here's a quick ad-hoc log of my readme which accompanies all installations.
Download from https://www.digitalvolcano.co.uk/duplicatecleaner.html
https://www.digitalvolcano.co.uk/download/DuplicateCleanerFree4_setup.exe

Name: DuplicateCleanerFree4_setup.exe
Size: 5832208 bytes (5 MB)
SHA256: 298C9A663E2C36928F21AB97D93B8879F72E4672AE1B2200C14FF2A6D3B8F58B

It wants to go in: C:\Program Files (x86)\Duplicate Cleaner Free
I put it in: C:\app\archiver\dupcleaner\volcano
The shortcut points to:
C:\app\archiver\dupcleaner\volcano\DuplicateCleaner.exe
It opens in: C:\Users\Public\Documents


Chris

unread,
Aug 7, 2018, 2:46:00 AM8/7/18
to
You could cut out the middleman and store the checksums with your backups.
The issue with using a duplicate finder down the line is that if it shows
they're different, you don't know which has changed.

R.Wieser

unread,
Aug 7, 2018, 4:03:00 AM8/7/18
to
Chris,

> The issue with using a duplicate finder down the line is that if
> it shows they're different, you don't know which has changed.

That is what the "last changed" dates are for I think. :-)

... unless you got a two whole branches of them.

Either way, the problem is moot. If they are different they sure as heck
are not duplicates, and both should be retained.

> You could cut out the middleman and store the checksums
> with your backups.

As you also should store the origional owner and his set permissions for the
file. If you don't you could have an un-doubled file backed up, but no way
to restore it to its individual owners.

@nospam:

> I use a duplicate finder to check that the ones I have backed
> up to DVD are identical to the ones on disk.

Trolling again ? You do not need a duplicate finder. All you need is a
"verify file A against copy B", which is something you got for free when
you installed your OS, and is called FC (short for File Compare).

Regards,
Rudy Wieser



nospam

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Aug 7, 2018, 8:08:59 AM8/7/18
to
In article <pkbjnh$8bt$1...@gioia.aioe.org>, R.Wieser
<add...@not.available> wrote:

> Chris,
>
> > The issue with using a duplicate finder down the line is that if
> > it shows they're different, you don't know which has changed.
>
> That is what the "last changed" dates are for I think. :-)
>
> ... unless you got a two whole branches of them.
>
> Either way, the problem is moot. If they are different they sure as heck
> are not duplicates, and both should be retained.

not necessarily. for example, one might want to save only the final
version of a document but other times, it might be the original that is
important, not an edited version. in some cases, every version needs to
be kept. sometimes the differences are only metadata and may not
matter, or maybe certain metadata does but not others. there is no hard
rule that applies to every situation.

> > You could cut out the middleman and store the checksums
> > with your backups.
>
> As you also should store the origional owner and his set permissions for the
> file. If you don't you could have an un-doubled file backed up, but no way
> to restore it to its individual owners.

which any decent backup utility would do.

> @nospam:
>
> > I use a duplicate finder to check that the ones I have backed
> > up to DVD are identical to the ones on disk.
>
> Trolling again ? You do not need a duplicate finder. All you need is a
> "verify file A against copy B", which is something you got for free when
> you installed your OS, and is called FC (short for File Compare).

i didn't write the part to which you're responding (see below), but any
decent backup utility will verify what it backs up without any need for
any additional tools.


In article <c2nhmd9cn574i7lsi...@4ax.com>, Shadow
<S...@dow.br> wrote:
> I use a duplicate finder to check that the ones I have backed

Shadow

unread,
Aug 7, 2018, 12:40:05 PM8/7/18
to
On Tue, 7 Aug 2018 10:02:48 +0200, "R.Wieser" <add...@not.available>
wrote:

>> I use a duplicate finder to check that the ones I have backed
>> up to DVD are identical to the ones on disk.
>
>Trolling again ? You do not need a duplicate finder. All you need is a
>"verify file A against copy B", which is something you got for free when
>you installed your OS, and is called FC (short for File Compare).

That was me.
"Found 7500 files with duplicate checksums. Please choose
which ones to delete, the ones on the backup DVD or the ones in your
download folder".
Does FC do that ?

Chris

unread,
Aug 7, 2018, 1:55:05 PM8/7/18
to
R.Wieser <add...@not.available> wrote:
> Chris,
>
>> The issue with using a duplicate finder down the line is that if
>> it shows they're different, you don't know which has changed.
>
> That is what the "last changed" dates are for I think. :-)

They can't be trusted.

> ... unless you got a two whole branches of them.
>
> Either way, the problem is moot. If they are different they sure as heck
> are not duplicates, and both should be retained.

Depends on why they're different. And when the difference occurred.

If one is corrupted there's no point in keeping it.

R.Wieser

unread,
Aug 7, 2018, 2:28:29 PM8/7/18
to
Shadow,

> That was me.

Yup. I noticed today.

> "Found 7500 files with duplicate checksums. Please choose
> which ones to delete, the ones on the backup DVD or the ones
> in your download folder".
> Does FC do that ?

Nope.

And if that is all your duplicate finder does (generate and compare hashes)
than I would suggest you delete it, and find yourself another, better
program. You know, one which, after finding files with the same hashes
actually checks if they have the same *contents*.

And pardon me, but your 'puter and backup DVD are *supposed to* have
duplicates. Its why you make backups. Why would you want to delete the
(duplicate) files on either of them ?

What you, in your "compare origional with backup" case *need* is a program
which will report the *opposite* of duplicates - The files which are only
available on *one* of the two media. That number should always be exactly
Zero. Any other indicates a major problem.

As for that 7500 number ? Its worthless, as its too big. There is no way
you will be able to go thru all of them (3750 pairs) without fouling up
somewhere, and either not delete a duplicate, or delete a duplicate which
actually isn't (is expected to be present in that particular folder).

In other words: You are using that duplicate finder wrong: You should use it
on your 'puter *before* making the backup (as part of the pre-backup
maintenance), to see if it has the same file floating around in multiple
folders. And you should thread lightly if-and-when you find any (and
rethink your storage strategy).

After the backup you should *at most* use a simple binary file compare using
the exact same filepaths (but for the source & destination basepath
difference ofcourse), nothing more.

Regards,
Rudy Wieser


Shadow

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Aug 7, 2018, 2:40:27 PM8/7/18
to
On Tue, 7 Aug 2018 20:28:13 +0200, "R.Wieser" <add...@not.available>
wrote:

>Shadow,
>
>> That was me.
>
>Yup. I noticed today.
>
>> "Found 7500 files with duplicate checksums. Please choose
>> which ones to delete, the ones on the backup DVD or the ones
>> in your download folder".
>> Does FC do that ?
>
>Nope.
>
>And if that is all your duplicate finder does (generate and compare hashes)
>than I would suggest you delete it, and find yourself another, better
>program. You know, one which, after finding files with the same hashes
>actually checks if they have the same *contents*.

Nope, I keep anything that's been altered. And back it up next
time.
>
>And pardon me, but your 'puter and backup DVD are *supposed to* have
>duplicates. Its why you make backups. Why would you want to delete the
>(duplicate) files on either of them ?

Because if they are backed up, the ones on disk are just using
up space.
>
>What you, in your "compare origional with backup" case *need* is a program
>which will report the *opposite* of duplicates - The files which are only
>available on *one* of the two media. That number should always be exactly
>Zero. Any other indicates a major problem.
>
>As for that 7500 number ? Its worthless, as its too big. There is no way
>you will be able to go thru all of them (3750 pairs) without fouling up
>somewhere, and either not delete a duplicate, or delete a duplicate which
>actually isn't (is expected to be present in that particular folder).

I just went though 20GB of photos with Duplicate Cleaner. Back
up to a DVD, eliminate duplicates on disk, back up another DVD's
worth, etc, until there were none.
Result = 20Gb of unique photos backed up.
>
>In other words: You are using that duplicate finder wrong: You should use it
>on your 'puter *before* making the backup (as part of the pre-backup
>maintenance)
I do.

>, to see if it has the same file floating around in multiple
>folders. And you should thread lightly if-and-when you find any (and
>rethink your storage strategy).
>
>After the backup you should *at most* use a simple binary file compare using
>the exact same filepaths (but for the source & destination basepath
>difference ofcourse), nothing more.

I just use this for movies, photos and stuff I download. I use
FreeFileSync for other data.

R.Wieser

unread,
Aug 7, 2018, 3:11:59 PM8/7/18
to
Shadow,

>>And if that is all your duplicate finder does (generate and compare
>> hashes) han I would suggest you delete it, and find yourself another,
>> better program. You know, one which, after finding files with the
>> same hashes actually checks if they have the same *contents*.
>
> Nope, I keep anything that's been altered. And back it up next
> time.

For some reason I cannot seem to correlate your reply with the statement I
made. What gives ?

> Because if they are backed up, the ones on disk are just
> using up space.

In other words: you are not making backups, you're offloading.

> I just went though 20GB of photos with Duplicate Cleaner.
> Back up to a DVD, eliminate duplicates on disk, back up
> another DVD's worth, etc, until there were none.

Find yourself a "backup" program which has a "move" option (deleting the
origional after the copy has been written & verified). That way you do not
need to go thru such a two-step process. With a bit of luck all you than
need to do is to replace the DVD with a blank one when the program asks for
it.

But why are you still using those DVDs ? Even a small USB drive can hold
at least 25 times that. A bit bigger one can hold a hundred. And USB
drives are reusable and can be updated per file.

Regards,
Rudy Wieser

P.s.
I would suggest you actually make *backups* of those photos of yours (and
not just offload them). You won't like it when your "offload" medium
suddenly turns into an "offline" one. :-)


R.Wieser

unread,
Aug 7, 2018, 3:16:12 PM8/7/18
to
Chris,

> They can't be trusted.

And neither can you trust your computer, OS or the program your find those
duplicates with. Your point ?

And as I already said, the whole point is moot. They are not duplicates,
thus no "which one should I delete?" choice exists.

> Depends on why they're different ...

See above.

> ... And when the difference occurred.

Good luck with finding a (freeware) duplicate-finding programe which is
aware of that
kind of thing.

> If one is corrupted there's no point in keeping it.

And that has to do with de-duplication ... what exactly ?

In other words, go bullshit someone else.

Regards,
Rudy Wieser



J. P. Gilliver (John)

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Aug 7, 2018, 3:18:50 PM8/7/18
to
In message <o7pjmd984ou10dof5...@4ax.com>, Shadow
<S...@dow.br> writes:
>On Tue, 7 Aug 2018 20:28:13 +0200, "R.Wieser" <add...@not.available>
>wrote:
[]
>>And pardon me, but your 'puter and backup DVD are *supposed to* have
>>duplicates. Its why you make backups. Why would you want to delete the
>>(duplicate) files on either of them ?
>
> Because if they are backed up, the ones on disk are just using
>up space.

I think we are perhaps confusing "backing up" with "archiving". The
terms - like all of language - change as time goes on, and no
intepretation is _wrong_; however, I think the interpretation of a
"backup" that RW (and I) use is the one currently in commoner use: a
backup is a safety copy made so that you can restore your everyday copy
if it gets damaged. _Your_ use is that when you've completed the
exercise, the one saved is the _only_ copy: then, if you actually want
to access it, you use the disc you've put it on. If it's a disc you use
frequently to access the files, that increases the chance the file (or
other files on that disc, or the disc itself) will be damaged -
certainly not what RW and I consider "backup". If they're files you
_don't_ use, then one could ask why you're keeping them at all, but that
could be for legal or countless other reasons.
[]
> I just went though 20GB of photos with Duplicate Cleaner. Back
>up to a DVD, eliminate duplicates on disk, back up another DVD's
>worth, etc, until there were none.
> Result = 20Gb of unique photos backed up.

(I think I'd say "archived" - to me "backed up" means "[emergency]
copies made". But I've covered that above.) For images, it's also useful
to have a Duplicate Image Finder, which finds duplicate images even if
they aren't byte-identical files: they might be in different image
formats, or rotated, or even just have different metadata. The one I'm
thinking of can also find them if they're different sizes (in pixels),
and also has a percentage control - depending on _why_ you're looking
for them, this can also eliminate a lot. (Obviously if you're into image
manipulation and want to keep all your iterations, this is of less use -
but if, say, you've downloaded a lot of images from diverse sources over
the years, it's good at finding copies.) The one I'm thinking of was I
think just called Duplicate Image Finder, but that's not easy to google
for (too broad), and you'd probably want a more modern something anyway
(that worked under XP, though I think would under 7 too).
>>
>>In other words: You are using that duplicate finder wrong: You should use it
>>on your 'puter *before* making the backup (as part of the pre-backup
>>maintenance)
> I do.

Right.
>
>>, to see if it has the same file floating around in multiple
>>folders. And you should thread lightly if-and-when you find any (and
>>rethink your storage strategy).
>>
>>After the backup you should *at most* use a simple binary file compare using
>>the exact same filepaths (but for the source & destination basepath
>>difference ofcourse), nothing more.
>
> I just use this for movies, photos and stuff I download. I use
>FreeFileSync for other data.
> []'s
So you're using it to check that a copy has worked? (I do this, in more
or less the way you describe!, using the duplicate finder to find and
remove the source files. I don't know why I'm doing this though -
they're probably files I'll never access!)

(I've just noticed how many 'groups this is going to: which Windows
_are_ you using? Since I suspect the answer people would give to the
subject question might well be different between XP and 10.)
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

"One of my dearest memories is playing the leader of a gang of gay Hell's
Angels
thundering across the Golden Gate bridge on a motorbike in fog, wearing full
Nazi regalia with a young man in a purple dress on the pillion petrified we'd
crash into the bay." Christopher Lee (1997). ["It was in _The Serial_."]

Big Al

unread,
Aug 7, 2018, 4:17:38 PM8/7/18
to
I use the one by Auslogics.
I also have used https://www.digitalvolcano.co.uk/duplicatecleaner.html

Arlen Holder

unread,
Aug 7, 2018, 5:23:15 PM8/7/18
to
On 7 Aug 2018 13:17:33 GMT, Big Al wrote:

> I use the one by Auslogics.
> I also have used https://www.digitalvolcano.co.uk/duplicatecleaner.html

That one showed up in a few of the reviews, but nothing showed up on top
consistently, which indicates a problem in general, in selection of
freeware.

Nonetheless, it's probably safe, at this early time point, to assume these
are the top three for most people.
1. Digital Volcano
2. Auslogics
3. CCleaner

Thanks!

J. P. Gilliver (John)

unread,
Aug 7, 2018, 7:09:11 PM8/7/18
to
In message <aH84Psck...@255soft.uk>, "J. P. Gilliver (John)"
<G6JP...@255soft.uk> writes:
[]
>(I think I'd say "archived" - to me "backed up" means "[emergency]
>copies made". But I've covered that above.) For images, it's also
>useful to have a Duplicate Image Finder, which finds duplicate images
>even if they aren't byte-identical files: they might be in different
>image formats, or rotated, or even just have different metadata. The
>one I'm thinking of can also find them if they're different sizes (in
>pixels), and also has a percentage control - depending on _why_ you're
>looking for them, this can also eliminate a lot. (Obviously if you're
>into image manipulation and want to keep all your iterations, this is
>of less use - but if, say, you've downloaded a lot of images from
>diverse sources over the years, it's good at finding copies.) The one
>I'm thinking of was I think just called Duplicate Image Finder, but
>that's not easy to google for (too broad), and you'd probably want a
>more modern something anyway (that worked under XP, though I think
>would under 7 too).

I found the one I used to use - google "Duplicate Image Finder" or DIF,
and "Runningman software", version 1.0.20. In theory it's payware (I
think I may have originally bought it), but the homesite is dead and
there's a password that works. Seems to work fine under 7.
[]
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

when people say they're perfectly happy without children, we don't have to
presume they're lying! - Paul Dolan, RT 2015/1/3-9

Shadow

unread,
Aug 7, 2018, 7:23:15 PM8/7/18
to
On Tue, 7 Aug 2018 21:11:33 +0200, "R.Wieser" <add...@not.available>
wrote:

>Shadow,
>
>>>And if that is all your duplicate finder does (generate and compare
>>> hashes) han I would suggest you delete it, and find yourself another,
>>> better program. You know, one which, after finding files with the
>>> same hashes actually checks if they have the same *contents*.
>>
>> Nope, I keep anything that's been altered. And back it up next
>> time.
>
>For some reason I cannot seem to correlate your reply with the statement I
>made. What gives ?
>
>> Because if they are backed up, the ones on disk are just
>> using up space.
>
>In other words: you are not making backups, you're offloading.
>
>> I just went though 20GB of photos with Duplicate Cleaner.
>> Back up to a DVD, eliminate duplicates on disk, back up
>> another DVD's worth, etc, until there were none.
>
>Find yourself a "backup" program which has a "move" option (deleting the
>origional after the copy has been written & verified). That way you do not
>need to go thru such a two-step process. With a bit of luck all you than
>need to do is to replace the DVD with a blank one when the program asks for
>it.

Yes, I did that. And my target drive crashed while I was
moving files. Never again. I prefer to double check.
>
>But why are you still using those DVDs ? Even a small USB drive can hold
>at least 25 times that. A bit bigger one can hold a hundred. And USB
>drives are reusable and can be updated per file.
>
>Regards,
>Rudy Wieser
>
>P.s.
>I would suggest you actually make *backups* of those photos of yours (and
>not just offload them). You won't like it when your "offload" medium
>suddenly turns into an "offline" one. :-)

I always make 2 copies, and DVDs last a lot longer than USB
drives. (theoretically over 100 years for DVDs as long as you compare
your 2 copies once a year or so).
My CD backups are over 30 years old, and all work fine.

Shadow

unread,
Aug 7, 2018, 7:32:27 PM8/7/18
to
On Tue, 7 Aug 2018 20:16:52 +0100, "J. P. Gilliver (John)"
<G6JP...@255soft.uk> wrote:

>In message <o7pjmd984ou10dof5...@4ax.com>, Shadow
><S...@dow.br> writes:
>>On Tue, 7 Aug 2018 20:28:13 +0200, "R.Wieser" <add...@not.available>
>>wrote:
>[]
>>>And pardon me, but your 'puter and backup DVD are *supposed to* have
>>>duplicates. Its why you make backups. Why would you want to delete the
>>>(duplicate) files on either of them ?
>>
>> Because if they are backed up, the ones on disk are just using
>>up space.
>
>I think we are perhaps confusing "backing up" with "archiving". The
>terms - like all of language - change as time goes on, and no
>intepretation is _wrong_; however, I think the interpretation of a
>"backup" that RW (and I) use is the one currently in commoner use: a
>backup is a safety copy made so that you can restore your everyday copy
>if it gets damaged. _Your_ use is that when you've completed the
>exercise, the one saved is the _only_ copy: then, if you actually want
>to access it, you use the disc you've put it on.

2 copies. It only takes a few more minutes and DVDs are dirt
cheap.
Yes, of course.

>(I do this, in more
>or less the way you describe!, using the duplicate finder to find and
>remove the source files. I don't know why I'm doing this though -
>they're probably files I'll never access!)

Well, in floppy days the source was corrupted so often we just
got into a habit of doing it.
>
>(I've just noticed how many 'groups this is going to: which Windows
>_are_ you using? Since I suspect the answer people would give to the
>subject question might well be different between XP and 10.)

Any OS needs backups and archiving. Just make sure you never
trust "The Cloud" and your data will be safe.

nospam

unread,
Aug 7, 2018, 7:45:03 PM8/7/18
to
In article <vgakmdlu8sboom6j8...@4ax.com>, Shadow
<S...@dow.br> wrote:

> Any OS needs backups and archiving. Just make sure you never
> trust "The Cloud" and your data will be safe.

actually, it's much safer in the cloud than at home, however, bandwidth
speeds make it very time consuming for most people, often impractical
for everything.

multiple copies in the cloud *and* at home *and* an offsite location is
ideal. each covers a different type of disaster.

nospam

unread,
Aug 7, 2018, 7:45:03 PM8/7/18
to
In article <v1akmdp4o17b16k4t...@4ax.com>, Shadow
<S...@dow.br> wrote:

> My CD backups are over 30 years old, and all work fine.

30 years ago is 1988.

what cd burner were you using in the mid-80s, before computers had
cd-rom drives, let alone cd burners?

<https://en.wikipedia.org/wiki/CD-R#History>
CD-R recording systems available in 1990 were similar to the washing
machine-sized Meridian CD Publisher, based on the two-piece rack
mount Yamaha PDS audio recorder costing $35,000, not including the
required external ECC circuitry for data encoding, SCSI hard drive
subsystem, and MS-DOS control computer. By 1992, the cost of typical
recorders was down to $10,000­12,000, and in September 1995,
Hewlett-Packard introduced its model 4020i manufactured by Philips,
which, at $995, was the first recorder to cost less than $1000.

in any event, buy a lottery ticket.

Shadow

unread,
Aug 7, 2018, 8:26:41 PM8/7/18
to
On Tue, 07 Aug 2018 19:45:00 -0400, nospam <nos...@nospam.invalid>
wrote:

>In article <v1akmdp4o17b16k4t...@4ax.com>, Shadow
><S...@dow.br> wrote:
>
>> My CD backups are over 30 years old, and all work fine.
>
>30 years ago is 1988.

Oh sht. My bad. My earliest backups are 1996. Make that 22
years. It was a single speed (on my machine) HP and it cost a fortune(
a thousand dollars on the black market), and lasted exactly 1 year.
Still, it was more than enough for my dialup speeds.
I think a CD was actually bigger than my HD back then .....

>
>what cd burner were you using in the mid-80s, before computers had
>cd-rom drives, let alone cd burners?
>
><https://en.wikipedia.org/wiki/CD-R#History>
> CD-R recording systems available in 1990 were similar to the washing
> machine-sized Meridian CD Publisher, based on the two-piece rack
> mount Yamaha PDS audio recorder costing $35,000, not including the
> required external ECC circuitry for data encoding, SCSI hard drive
> subsystem, and MS-DOS control computer. By 1992, the cost of typical
> recorders was down to $10,000­12,000, and in September 1995,
> Hewlett-Packard introduced its model 4020i manufactured by Philips,
> which, at $995, was the first recorder to cost less than $1000.
>
>in any event, buy a lottery ticket.

Not my case.

Nil

unread,
Aug 7, 2018, 9:21:09 PM8/7/18
to
On 07 Aug 2018, Arlen Holder <arlen...@nospam.net> wrote in
microsoft.public.windowsxp.general:

> You need to ignore that troll "nospam" as he has never posted with
> any helpful intent, and where there are entire threads about his
> mental status.

There are also posts about YOUR mental status. Should we ignore you, too?

Arlen Holder

unread,
Aug 7, 2018, 11:37:10 PM8/7/18
to
On 7 Aug 2018 18:21:06 GMT, Nil wrote:

> Should we ignore you, too?

I pray to God that you do, Nil.
You've never once posted anything of value to anyone. Ever.
Go away.
Please.

Chris

unread,
Aug 8, 2018, 3:11:24 AM8/8/18
to
Shadow <S...@dow.br> wrote:
> On Tue, 7 Aug 2018 20:16:52 +0100, "J. P. Gilliver (John)"
> <G6JP...@255soft.uk> wrote:
>
>> In message <o7pjmd984ou10dof5...@4ax.com>, Shadow
>> <S...@dow.br> writes:
>>> On Tue, 7 Aug 2018 20:28:13 +0200, "R.Wieser" <add...@not.available>
>>> wrote:
>> []
>>>> And pardon me, but your 'puter and backup DVD are *supposed to* have
>>>> duplicates. Its why you make backups. Why would you want to delete the
>>>> (duplicate) files on either of them ?
>>>
>>> Because if they are backed up, the ones on disk are just using
>>> up space.
>>
>> I think we are perhaps confusing "backing up" with "archiving". The
>> terms - like all of language - change as time goes on, and no
>> intepretation is _wrong_; however, I think the interpretation of a
>> "backup" that RW (and I) use is the one currently in commoner use: a
>> backup is a safety copy made so that you can restore your everyday copy
>> if it gets damaged. _Your_ use is that when you've completed the
>> exercise, the one saved is the _only_ copy: then, if you actually want
>> to access it, you use the disc you've put it on.
>
> 2 copies. It only takes a few more minutes and DVDs are dirt
> cheap.

And unreliable. Writable DVDs are not suitable for archiving.

Why not just use an external hard drive? Cheaper, simpler and more
reliable.

Chris

unread,
Aug 8, 2018, 3:15:05 AM8/8/18
to
R.Wieser <add...@not.available> wrote:
> Chris,
>
>> They can't be trusted.
>
> And neither can you trust your computer, OS or the program your find those
> duplicates with. Your point ?

Er, ok. With that attitude just shut down the computer and throw it out the
window.

R.Wieser

unread,
Aug 8, 2018, 4:15:16 AM8/8/18
to
Shadow,

> Yes, I did that. And my target drive crashed while I
> was moving files. Never again. I prefer to double
> check.

That is why you need a *good* offloader/backup program. One which only
deletes the origional files after the *full* backup/offload has been
completed.

>>But why are you still using those DVDs ?
...
> DVDs last a lot longer than USB drives.

Only if you do not use the ones for home usage. Some of them become
unreadable in as short as 5 years or so.

But yes, if all you want is storage (in a dry, dark place I presume) than
DVDs are not too bad of a choice.

Regards,
Rudy Wieser


R.Wieser

unread,
Aug 8, 2018, 4:44:26 AM8/8/18
to
Chris,

>> 2 copies. It only takes a few more minutes and DVDs are dirt
>> cheap.
>
> And unreliable. Writable DVDs are not suitable for archiving.

No, You need the *unwritable* ones. Those are much better suited for
Shadows task. :-)

If handled with some care a good CD/DVD can easily outlast a drive.
Magnetism fades away you know. And that becomes a problem when you do not
really use the drive (meaning: do not give it a chance to refresh sectors).

> Why not just use an external hard drive? Cheaper, simpler and
> more reliable.

Yeah, I already asked him that (without the "more reliable" and "cheaper"
stacked to it though - both of them are dependant on a few factors and
(thus)
rather questionable). 12 hours back on the minute

Regards,
Rudy Wieser


R.Wieser

unread,
Aug 8, 2018, 4:52:21 AM8/8/18
to
Chris,

>> And neither can you trust your computer, OS or the program your find
>> those
>> duplicates with. Your point ?
>
> Er, ok. With that attitude just shut down the computer and throw it out
> the
> window.

Exactly. So, please explain to me why you cannot trust that "last written"
time. And than why you still have a 'puter infront of you.

Regards,
Rudy Wieser


Chris

unread,
Aug 8, 2018, 8:00:09 AM8/8/18
to
Because those timestamps can be modified by poorly written software or by
improperly copying/moving the files. Filesystem issues can also render
timestamps meaningless.

They aren't a reliable piece of information unlike a checksum.


nospam

unread,
Aug 8, 2018, 8:18:20 AM8/8/18
to
In article <pkeah6$el9$1...@gioia.aioe.org>, R.Wieser
<add...@not.available> wrote:

> If handled with some care a good CD/DVD can easily outlast a drive.

i've slowly been migrating old cd/dvds to hard drives, only to find
that quite a few discs have issues. all of the discs were safely stored
and rarely used, until the migration.

most discs took a couple of minutes to read (i.e., normal), but some
took 10-15 minutes each to read and a few are not readable at all.

these were all quality cds, not the cheap crap.

the dyes in cd/dvds degrade. there's no way around that.

> Magnetism fades away you know. And that becomes a problem when you do not
> really use the drive (meaning: do not give it a chance to refresh sectors).

the main issue with hard drives that sit unused are frozen bearings.

however, fading away can be an issue with some ssds.

nothing lasts forever.

R.Wieser

unread,
Aug 8, 2018, 10:27:58 AM8/8/18
to
Chris,

>> Exactly. So, please explain to me why you cannot trust that "last
> written" time. And than why you still have a 'puter infront of you.
>
> Because those timestamps can be modified by poorly written software

So, vaguely referred to "poorly written software" can/will just change those
timestamps (but nothing more), and both your "diplicates finder" and your OS
do not fall in that range - for which reason please ?

> or by improperly copying/moving the files.

When you do something "improperly" a lot more can be changed/damaged than
just that timestamp (owner, permissions). *Especially* when you use
"poorly written software". So again, your point ?

> Filesystem issues can also render timestamps meaningless.

Lolz. You just *ran* into that one, didn't you ? With open eyes no less.

I mentioned that if you cannot trust those timestamps you also should not
trust your OS (or any programs on it) - to which you reponded that that was
a negative attitude - and now you're actually telling me that the OS could
well not be trustworthy in this regard ?

> They aren't a reliable piece of information unlike a checksum.

True, but now you're trying to change the subject to "what is the best
method to detect changes between two files", which I'm not going along with.

Besides, the using of checksums/hashes has its own problems. Like the stored
hash and its file going outof sync. Or maybe some "poorly written software"
generating weak hashes with lots of collisions ... :-)

Bottom line, you still have not told me (apart from some FUD) why I should
actually distrust the last written timestamp. Or why you still own a
'puter.

Or in simpler words: why do you distrust that timestamp, but still trust
your 'puter for everything else ...


Also, you have lost sight of the reason what that timestamp used for. To
detect if the file has changed. If that timestamp has changed you may
assume that the file has changed, and thus needs to be re-backupped. And
that regardles of who actually changed it. Or why.

Regards,
Rudy Wieser

P.s.
If you have "poorly written software" on your 'puter I would suggest you
delete it and find something better. :-p


nospam

unread,
Aug 8, 2018, 10:39:08 AM8/8/18
to
In article <pkeula$1h9j$1...@gioia.aioe.org>, R.Wieser
<add...@not.available> wrote:

> Also, you have lost sight of the reason what that timestamp used for. To
> detect if the file has changed. If that timestamp has changed you may
> assume that the file has changed, and thus needs to be re-backupped. And
> that regardles of who actually changed it. Or why.

except when the time stamp changes simply by copying a file yet its
contents did *not* change. in other words, two files with different
time stamps can be identical.

Shadow

unread,
Aug 8, 2018, 12:07:50 PM8/8/18
to
On Wed, 8 Aug 2018 07:11:21 -0000 (UTC), Chris <ithi...@gmail.com>
wrote:
I'm still recovering from the last crash. 2 TB of backups or
archives or whatever down the drain. The drive lasted 4 months. No
warranty possible as it contains personal files. You have to hand it
in so Seagate can "refurbish it" and sell it to another sucker, and
probably sell all your data once they replace the controller.

Checking
1998 programming - TDK CD-R 650MB 74 Min (everything from Softice to C
compilers, assemblers, editors, tutors etc. Sadly, most installers are
16 bit)
2000 books - Memorex
2000 Diablo 2 - 2 disks TDK

All 100% readable with DVDDisaster. Use decent media and keep it in a
cool, dark and dry place.

Checking
Megaupload - keep your files safe on "The Cloud"
Gone - 100% failure

nospam

unread,
Aug 8, 2018, 12:17:35 PM8/8/18
to
In article <v62mmdlgtfd5huvpr...@4ax.com>, Shadow
<S...@dow.br> wrote:

> >Why not just use an external hard drive? Cheaper, simpler and more
> >reliable.
>
> I'm still recovering from the last crash. 2 TB of backups or
> archives or whatever down the drain. The drive lasted 4 months. No
> warranty possible as it contains personal files.

next time, encrypt it, and also make more than one backup.



> Checking
> Megaupload - keep your files safe on "The Cloud"
> Gone - 100% failure

a cloud service focusing on piracy shut down. imagine that.

meanwhile, amazon, google, apple, microsoft, dropbox, etc. are still
around and not likely to go away any time soon, certainly not in our
lifetimes.

hard drives also crash, as did yours. 100% failure there too.

nothing is guaranteed, which is why one should have *multiple* backups
and in mulitple locations.

ask the people affected by the california wildfires, or the hurricanes
last year, where everything in their houses was destroyed, whether they
prefer a cloud backup or a local (and now non-existent) backup.

Shadow

unread,
Aug 8, 2018, 12:42:54 PM8/8/18
to
On Wed, 08 Aug 2018 12:17:32 -0400, nospam <nos...@nospam.invalid>
wrote:

>In article <v62mmdlgtfd5huvpr...@4ax.com>, Shadow
><S...@dow.br> wrote:
>
>> >Why not just use an external hard drive? Cheaper, simpler and more
>> >reliable.
>>
>> I'm still recovering from the last crash. 2 TB of backups or
>> archives or whatever down the drain. The drive lasted 4 months. No
>> warranty possible as it contains personal files.
>
>next time, encrypt it, and also make more than one backup.

Yes, still trying to figure out the most reliable encrypted
backup.A real time sync would be best, as in just replace the bad
drive(assuming the backup goes bad) and it would boot into your old
workspace. But encrypted ? I could just carry on backupping films and
photos to DVDs.
As to Cloud services, I'll take my luck with hurricanes and
wildfires. Until hurricanes and wildfires figure out how to sell your
data too, of course.
Are Seagate and Western Digital the only choices left ? So
much for capitalism.

Any ideas as to an encrypted system, "type password at boot"
and with a real-time mirror to a second HD, ie, anything changed in
main drive will also be changed in second drive ?
[]'s
>
>
>
>> Checking
>> Megaupload - keep your files safe on "The Cloud"
>> Gone - 100% failure
>
>a cloud service focusing on piracy shut down. imagine that.
>
>meanwhile, amazon, google, apple, microsoft, dropbox, etc. are still
>around and not likely to go away any time soon, certainly not in our
>lifetimes.
>
>hard drives also crash, as did yours. 100% failure there too.
>
>nothing is guaranteed, which is why one should have *multiple* backups
>and in mulitple locations.
>
>ask the people affected by the california wildfires, or the hurricanes
>last year, where everything in their houses was destroyed, whether they
>prefer a cloud backup or a local (and now non-existent) backup.

J. P. Gilliver (John)

unread,
Aug 8, 2018, 6:52:05 PM8/8/18
to
In message <hj6mmd9rtno074r4u...@4ax.com>, Shadow
<S...@dow.br> writes:
[]
> Any ideas as to an encrypted system, "type password at boot"
>and with a real-time mirror to a second HD, ie, anything changed in
>main drive will also be changed in second drive ?
[]
I think one of the RAIDs (0 or 1?) will do the second bit; I assume they
can be used with type-password-at-boot type systems, but I don't know.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

The motto of the Royal Society is: 'Take nobody's word for it'. Scepticism has
value. - Brian Cox, RT 2015/3/14-20

nospam

unread,
Aug 8, 2018, 6:55:50 PM8/8/18
to
In article <rIiEsTDe...@255soft.uk>, J. P. Gilliver (John)
<G6JP...@255soft.uk> wrote:

> > Any ideas as to an encrypted system, "type password at boot"
> >and with a real-time mirror to a second HD, ie, anything changed in
> >main drive will also be changed in second drive ?
>
> I think one of the RAIDs (0 or 1?) will do the second bit; I assume they
> can be used with type-password-at-boot type systems, but I don't know.

most nases support encryption, regardless of which raid it's set up as,
and some of which have a hardware encryption chip so there's little to
no impact on performance.

and raid 0 is for performance, not backups.

R.Wieser

unread,
Aug 9, 2018, 4:45:39 AM8/9/18
to
Chris,

[quote=me]
Also, you have lost sight of the reason what that timestamp used for.
[/quote]

Maybe even put simpler:

# When the "last changed" times differ (but the contents are the same) than
:

1) the "duplicate finder" will consider them as different. The negative site
of that will be that you will have two copies instead of the desired single
one.

2) the backup program makes a copy of it. The negative side of that would
be that it needs more time and storage space to complete.

# The chance that both files "last changed" times do actually match (after
some "poorly written software" has altered it) is rather small
(understatement).

In other words, a false positive (the files are considered the same when
they are not) is rather unlikely, and a false negative isn't destructive.


But even if those "last changed" timestamps would match (like after some
PEBKAC has run a "touch" on its whole drive), its just *one* part in the
whole "are the files the same" check, which includes size and (when
backupping/comparing with a backup) the full filepath (among others).

Regards,
Rudy Wieser


Shadow

unread,
Aug 9, 2018, 9:24:54 AM8/9/18
to
On Wed, 8 Aug 2018 23:50:06 +0100, "J. P. Gilliver (John)"
<G6JP...@255soft.uk> wrote:

>In message <hj6mmd9rtno074r4u...@4ax.com>, Shadow
><S...@dow.br> writes:
>[]
>> Any ideas as to an encrypted system, "type password at boot"
>>and with a real-time mirror to a second HD, ie, anything changed in
>>main drive will also be changed in second drive ?
>[]
>I think one of the RAIDs (0 or 1?) will do the second bit; I assume they
>can be used with type-password-at-boot type systems, but I don't know.

I'm still recovering from a rather large surgery I had 5 days
ago, and my head is full of narcotics. I hate narcotics, having
trouble thinking. In my perception, the Bouffant's posts have gone
from extremely imbecilic to just stupid. That's how bad my thinking
process is ATM.

Re backup = That's what I want. I don't mind paying for a
second or third HD if they are kept strictly in sinc, and preferably
if the backup drives do not appear in explorer. I would still backup
or archive personal photos, movies, letters, documents etc to DVDs, as
they are irreplaceable, and it's possible a power surge could burn out
both HDs at once.
So a RAID with only the basic boot-up files not encrypted, and
no network access until the drives have been unencrypted and firewalls
etc are all working.
How would I go about that ?
[]s

Terry Pinnell

unread,
Aug 9, 2018, 9:47:34 AM8/9/18
to
Arlen Holder <arlen...@nospam.net> wrote:

>Jesus...There are so many - what do you use for a freeware duplicate file
>finder on Windows?
>
>Googling, I find so many it's not funny...where you know there's a problem
>when no two articles even have agreement on the top few.
>
>First I tried the canonical duplicate file remover from Microsoft...
>Microsoft Duplicate File Remover
><https://www.microsoft.com/en-us/p/duplicate-file-remover/9nblggh4sqnp>
>
>But it was too much GUI and too little customization.
><http://www.bild.me/bild.php?file=9081255duplicatefileremover.jpg>
>
>Then I searched for better duplicate file removers, and was aghast that
>there is very little consensus among the "reviews" (many of which, I know,
>are simply shills).
>
>The Best Duplicate File Finder for Windows
>* dupeGuru <https://dupeguru.voltaicideas.net/>
>* Ccleaner <https://www.ccleaner.com/ccleaner>
><https://lifehacker.com/the-best-duplicate-file-finder-for-windows-1696492476>
>
>What Is the Best Duplicate File Finder?
><https://www.easyduplicatefinder.com/best-duplicate-file-finder.html>
>
>How to Find and Remove Duplicate Files on Windows
><https://www.howtogeek.com/200962/how-to-find-and-remove-duplicate-files-on-windows/>
>
>5 Best Free Duplicate File Finder Software for Windows
><https://www.cisdem.com/resource/best-free-duplicate-file-finder-for-windows.html>
>
>5 Best Free Duplicate File Finder and Remover
><http://perfectgeeks.com/free-duplicate-file-finder-remover/>
><https://www.top5freeware.com/duplicate-file-finder>
>* Auslogics Duplicate File Finder <https://softfamous.com/auslogics-duplicate-file-finder/>
>* AllDup <https://softfamous.com/alldup/>
>* CloneSpy <http://www.filesriver.com/app/117/clonespy>
>* Fast Duplicate File Finder <http://www.filesriver.com/app/118/mindgems-fast-duplicate-file-finder>
>* Anti-Twin <http://www.filesriver.com/app/119/anti-twin>
>
>26 Best Free Duplicate File Finders
><https://listoffreeware.com/list-of-best-free-duplicate-file-finder/>
>
>What do you use for a freeware duplicate file finder on Windows?

I recently did a fair bit of searching and settled on a commercial
program, Duplicate Cleaner Pro, after briefly trying the free version.
Basically because it looked more versatile than most. And I'm not so
stingy about buying stuff nowadays.

https://www.duplicatecleaner.com/

Too early to give a useful assessment, but I've found no serious issues
on the few occasions I've used it to prune large folders of photos.

Terry, East Grinstead, UK

Chris

unread,
Aug 10, 2018, 3:37:13 AM8/10/18
to
R.Wieser <add...@not.available> wrote:
> Chris,
>
>>> Exactly. So, please explain to me why you cannot trust that "last
>> written" time. And than why you still have a 'puter infront of you.
>>
>> Because those timestamps can be modified by poorly written software
>
> So, vaguely referred to "poorly written software" can/will just change those
> timestamps (but nothing more), and both your "diplicates finder" and your OS
> do not fall in that range - for which reason please ?

I don't have duplicates finder. The OS is written to a much higher standard
than most userland apps.

>> or by improperly copying/moving the files.
>
> When you do something "improperly" a lot more can be changed/damaged than
> just that timestamp (owner, permissions). *Especially* when you use
> "poorly written software". So again, your point ?

You just made it for me. Checksums are much better than last changed
timestamps.

>> Filesystem issues can also render timestamps meaningless.
>
> Lolz. You just *ran* into that one, didn't you ? With open eyes no less.
>
> I mentioned that if you cannot trust those timestamps you also should not
> trust your OS (or any programs on it) - to which you reponded that that was
> a negative attitude - and now you're actually telling me that the OS could
> well not be trustworthy in this regard ?

Whoosh! The OS and filesystem are not synonymous.

>> They aren't a reliable piece of information unlike a checksum.
>
> True, but now you're trying to change the subject to "what is the best
> method to detect changes between two files", which I'm not going along with.

This was my original point to Shadow which you butted in on. Is there's one
of us who's changing the subject, it's you.

> Besides, the using of checksums/hashes has its own problems. Like the stored
> hash and its file going outof sync. Or maybe some "poorly written software"
> generating weak hashes with lots of collisions ... :-)

Nothing's perfect. However comparing timestamps is much worse than
checksums.

>
> Also, you have lost sight of the reason what that timestamp used for. To
> detect if the file has changed.

No. That is not what a timestamp is for. All it tells you is when it was
last re-saved. You cannot make any judgement on state change.

For example I have a file with a timestamp of "01 April 2015 11:32:05". Has
the file changed?

> If that timestamp has changed you may
> assume that the file has changed,

Nope. A file can be opened and re-saved without any changes occurring.

Why is all this so hard for you to understand?

> P.s.
> If you have "poorly written software" on your 'puter I would suggest you
> delete it and find something better. :-p

Well, it is Windows. It comes with the territory :-^)



R.Wieser

unread,
Aug 10, 2018, 7:30:04 AM8/10/18
to
Chris,

> The OS is written to a much higher standard than most
> userland apps.

Kiddo, you just told me that even mere moving or copying could muck around
with the timestamp, so where are you taking that "higher standard" from ?

Also, you seem to be thinking that for "badly written software" changing
that "last written" timestamp is something that a program can "just do" -
without any particulary intent or reason. Newsflash: Its harder than you
think. :-)

> You just made it for me. Checksums are much better than last
> changed timestamps.

I would strongly suggest you read it again. I was making a case where doing
something "improperly" would most likely damage a lot more than just a
timestamp. In other words, the changed timestamp would than be the least
of your concerns.

> Checksums are much better than last changed timestamps.

Again trying to change the subject ?

> Whoosh! The OS and filesystem are not synonymous.

Just like checksums and hashes are not. You don't give a flying fuck about
it, but now trying to using distinction like that ? Really ?

And yes, I'm quite aware of it. But I mostly do not make a point of it
(especially not when its not relevant to the problem) as it just confuses
the issue. Just like I have not pointed out the difference between a
checksum and a hash.

Also, when was the last time you bought your OS and your filesystem
seperatily ? Lets guess ... Never ?

>> True, but now you're trying to change the subject to "what is the best
>> method to detect changes between two files", which I'm not going along
>> with.
>
> This was my original point to Shadow which you butted in on. Is there's
> one
> of us who's changing the subject, it's you.

[quote]
> I use a duplicate finder to check that the ones I have backed
> up to DVD are identical to the ones on disk. Good duplicate
> finders use hashes and checksums.
> []'s

You could cut out the middleman and store the checksums with your
backups.
The issue with using a duplicate finder down the line is that if it shows
they're different, you don't know which has changed.
[/quote]

This is what I responded to : Using a duplicate finder as part of a backup
process. Would you like to try again ?

> Nothing's perfect. However comparing timestamps is much worse
> than checksums.

You have said that several times, but no matter what I say you have not even
*tried* to come up with anything underbuilding it - other than a vague
hand-waving to "poorly written software", which I think I shot outof the
water.

> No. That is not what a timestamp is for. All it tells you is when it was
> last re-saved. You cannot make any judgement on state change.

True. The question is, if you have not changed anything, why would you
re-save ? And what if its intentional (the file is ment to be regarded as
the most recent one) ?

> For example I have a file with a timestamp of "01 April 2015 11:32:05".
> Has the file changed?

Im upping you one: How does your "lets take a checksum" indicate a change
(or not) ?

And when you figured that out, do you think I may also do a compare (of that
timestamp against another one) ?

>> If that timestamp has changed you may
>> assume that the file has changed,
>
> Nope. A file can be opened and re-saved without any changes
> occurring.

Yes, thats a possibility. But notice the "you may assume that" (for most,
if not all, intents and purposes). In other words, I'm quite aware of it.

Also, already replied to (repeating yourself doesn't make your case
stronger)

> Why is all this so hard for you to understand?

It isn't, and I've given several indications of that in my previous posts.



But I have the same question for you: With all my explanation, why don't you
understand that "just" using the "last written" timestamp normally works,
and when not it isn't destructive ?

Also, how is it that you seem to be acutily aware of how bad using a
last-written timestamp is, but have given no indication to the problems your
preferred method of using hashes has ? In short: You are not even
*trying* to compare the two.


And FYI, comparing hashes is just *one* step in the process. Which includes
generating them from full contents of the sourcefiles file (costs time). If
the compare is done to a backup hashes need to be generated for them too
{1}. Than comparing them and when they match *compare the actual file
contents* (costs time) to be sure they are really the same (and not just
hash collisions).

{1} If you are thinking about storing the hashes of the backupped files
somewhere that file can get lost, altered or corrupted. Or, even worse,
someone could alter a file on the backup which throws the list outof sync.

My suggested "compare 'last written' timestamps" (among a few things) do not
involve any of that ...

Bottom line: both methods have their pros and cons. The method involving
hashing will find *all* duplicates, but will cost a *lot* of time. The
"last written" method is fast, but could miss a few files which contents
have not actually changed.


But lets end this, shall we ? You seem to be convinced that I'm not
understanding any of it, as I'm convinced that its you (who doesn't even
try). :-)

Regards,
Rudy Wieser


Michael Scott

unread,
Dec 5, 2023, 8:22:33 AM12/5/23
to
On Monday, August 6, 2018 at 5:14:13 p.m. UTC-4, Shadow wrote:
> On Mon, 6 Aug 2018 21:06:01 -0000 (UTC), Arlen Holder
> <arlen...@nospam.net> wrote:
>
> >Jesus...There are so many - what do you use for a freeware duplicate file
> >finder on Windows?
>
>
> --
> Don't be evil - Google 2004
> We have a new policy - Google 2012
Love the signature!
Memories of Groucho!😕
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