Can I rely on "copy" command?

[Guest Walter R.]

I often have occasion to copy or move large blocks of files from one

partition to another.

 

Win XP SP2 has never told me yet that it has lost a byte here or a byte

there. Can I assume that all transfers are done flawlessly and with zero

data loss? Will Windows let me know if it accidentally loses or mangles a

few bytes while transferring data?

 

--

Walter

http://www.rationality.net

-

[Guest Bob I]

Re: Can I rely on "copy" command?

 

 

 

Walter R. wrote:

> I often have occasion to copy or move large blocks of files from one

> partition to another.

>

> Win XP SP2 has never told me yet that it has lost a byte here or a byte

> there. Can I assume that all transfers are done flawlessly and with zero

> data loss? Will Windows let me know if it accidentally loses or mangles a

> few bytes while transferring data?

>

 

How would it know? It doesn't do a bit by bit copy verify. On the other

hand, when the system doesn't suffer hardware failure it works great.

The majority of the "data loss" is user error, followed by outright

drive failure. (which the user didn't backup)

[Guest smlunatick]

Re: Can I rely on "copy" command?

 

On Sep 5, 5:59 pm, "Walter R." <we...@example.com> wrote:

> I often have occasion to copy or move large blocks of files from one

> partition to another.

>

> Win XP SP2  has never told me yet that it has lost a byte here or a byte

> there. Can I assume that all transfers are done flawlessly and with zero

> data loss? Will Windows let me know if it accidentally loses or mangles a

> few bytes while transferring data?

>

> --

> Walterwww.rationality.net

> -

 

Nothing is every fool-proof. Xcopy has been around for some time and

may be reliable.

[Guest Walter R.]

Re: Can I rely on "copy" command?

 

Well, I was wondering if it uses some kind of checksum before and after the

transfer. It should. Otherwise, Windows would be inherently unreliable.

 

Anyone know?

 

--

Walter

http://www.rationality.net

-

"Bob I" <birelan@yahoo.com> wrote in message

news:u5P7Bp3DJHA.3352@TK2MSFTNGP05.phx.gbl...

>

>

> Walter R. wrote:

>

>> I often have occasion to copy or move large blocks of files from one

>> partition to another.

>>

>> Win XP SP2 has never told me yet that it has lost a byte here or a byte

>> there. Can I assume that all transfers are done flawlessly and with zero

>> data loss? Will Windows let me know if it accidentally loses or mangles a

>> few bytes while transferring data?

>>

>

> How would it know? It doesn't do a bit by bit copy verify. On the other

> hand, when the system doesn't suffer hardware failure it works great. The

> majority of the "data loss" is user error, followed by outright drive

> failure. (which the user didn't backup)

>

[Guest Pegasus \(MVP\)]

Re: Can I rely on "copy" command?

 

 

"smlunatick" <yveslec@gmail.com> wrote in message

news:dc32b5c6-2208-4f87-8116-4146a5ca69c3@y38g2000hsy.googlegroups.com...

On Sep 5, 5:59 pm, "Walter R." <we...@example.com> wrote:

> I often have occasion to copy or move large blocks of files from one

> partition to another.

>

> Win XP SP2 has never told me yet that it has lost a byte here or a byte

> there. Can I assume that all transfers are done flawlessly and with zero

> data loss? Will Windows let me know if it accidentally loses or mangles a

> few bytes while transferring data?

>

> --

> Walterwww.rationality.net

> -

 

Nothing is every fool-proof. Xcopy has been around for some time and

may be reliable.

 

==============

 

.. . . and it has a /v (verify) switch!

[Guest Bob I]

Re: Can I rely on "copy" command?

 

 

 

Pegasus (MVP) wrote:

> "smlunatick" <yveslec@gmail.com> wrote in message

> news:dc32b5c6-2208-4f87-8116-4146a5ca69c3@y38g2000hsy.googlegroups.com...

> On Sep 5, 5:59 pm, "Walter R." <we...@example.com> wrote:

>

>>I often have occasion to copy or move large blocks of files from one

>>partition to another.

>>

>>Win XP SP2 has never told me yet that it has lost a byte here or a byte

>>there. Can I assume that all transfers are done flawlessly and with zero

>>data loss? Will Windows let me know if it accidentally loses or mangles a

>>few bytes while transferring data?

>>

>>--

>>Walterwww.rationality.net

>>-

>

>

> Nothing is every fool-proof. Xcopy has been around for some time and

> may be reliable.

>

> ==============

>

> . . . and it has a /v (verify) switch!

>

 

Don't bet on that.

 

Using /v

Windows XP does not use this command. It is accepted only for

compatibility with MS-DOS files.

 

and

 

VERIFY ON, COPY /V, XCOPY /V Commands Do Not Compare Data

http://support.microsoft.com/kb/126457

[Guest Leythos]

Re: Can I rely on "copy" command?

 

In article <ODFwzi3DJHA.5316@TK2MSFTNGP04.phx.gbl>, wer25@example.com

says...

> I often have occasion to copy or move large blocks of files from one

> partition to another.

>

> Win XP SP2 has never told me yet that it has lost a byte here or a byte

> there. Can I assume that all transfers are done flawlessly and with zero

> data loss? Will Windows let me know if it accidentally loses or mangles a

> few bytes while transferring data?

>

>

 

Use the FREE ROBOCOPY utility from MS, it's faster, has reporting, and

even output a log to a file.

 

--

- Igitur qui desiderat pacem, praeparet bellum.

- Calling an illegal alien an "undocumented worker" is like calling a

drug dealer an "unlicensed pharmacist"

spam999free@rrohio.com (remove 999 for proper email address)

[Guest John McGaw]

Re: Can I rely on "copy" command?

 

Walter R. wrote:

> Well, I was wondering if it uses some kind of checksum before and after the

> transfer. It should. Otherwise, Windows would be inherently unreliable.

>

> Anyone know?

>

 

Well, even if _XP_ doesn't do it, there is nothing to stop _you_ from

generating a checksum or hash before the copy and then it afterward to make

sure that it worked properly. You could do a simple CSV. Or do an MD5. Or

even generate 10% of PAR2 files and copy them along with the originals and

then your copies will be to a large extent self-repairing even if something

goes awry.

 

John McGaw

http://johnmcgaw.com

[Guest Pegasus \(MVP\)]

Re: Can I rely on "copy" command?

 

 

"Bob I" <birelan@yahoo.com> wrote in message

news:%23OgTn83DJHA.4676@TK2MSFTNGP05.phx.gbl...

>

>

> Pegasus (MVP) wrote:

>

>> "smlunatick" <yveslec@gmail.com> wrote in message

>> news:dc32b5c6-2208-4f87-8116-4146a5ca69c3@y38g2000hsy.googlegroups.com...

>> On Sep 5, 5:59 pm, "Walter R." <we...@example.com> wrote:

>>

>>>I often have occasion to copy or move large blocks of files from one

>>>partition to another.

>>>

>>>Win XP SP2 has never told me yet that it has lost a byte here or a byte

>>>there. Can I assume that all transfers are done flawlessly and with zero

>>>data loss? Will Windows let me know if it accidentally loses or mangles a

>>>few bytes while transferring data?

>>>

>>>--

>>>Walterwww.rationality.net

>>>-

>>

>>

>> Nothing is every fool-proof. Xcopy has been around for some time and

>> may be reliable.

>>

>> ==============

>>

>> . . . and it has a /v (verify) switch!

>

> Don't bet on that.

>

> Using /v

> Windows XP does not use this command. It is accepted only for

> compatibility with MS-DOS files.

>

> and

>

> VERIFY ON, COPY /V, XCOPY /V Commands Do Not Compare Data

> http://support.microsoft.com/kb/126457

>

 

Well, I learn something new every day! BTW, I assume you meant to write

Windows XP does not use this switch instead of

Windows XP does not use this command.

because the command "xcopy.exe" is fully supported under WinXP (even though

it is now deprecated in favour of robocopy).

[Guest HeyBub]

Re: Can I rely on "copy" command?

 

Bob I wrote:

> Pegasus (MVP) wrote:

>

>> "smlunatick" <yveslec@gmail.com> wrote in message

>> news:dc32b5c6-2208-4f87-8116-4146a5ca69c3@y38g2000hsy.googlegroups.com...

>> On Sep 5, 5:59 pm, "Walter R." <we...@example.com> wrote:

>>

>>> I often have occasion to copy or move large blocks of files from one

>>> partition to another.

>>>

>>> Win XP SP2 has never told me yet that it has lost a byte here or a

>>> byte there. Can I assume that all transfers are done flawlessly and

>>> with zero data loss? Will Windows let me know if it accidentally

>>> loses or mangles a few bytes while transferring data?

>>>

>>> --

>>> Walterwww.rationality.net

>>> -

>>

>>

>> Nothing is every fool-proof. Xcopy has been around for some time and

>> may be reliable.

>>

>> ==============

>>

>> . . . and it has a /v (verify) switch!

>>

>

> Don't bet on that.

>

> Using /v

> Windows XP does not use this command. It is accepted only for

> compatibility with MS-DOS files.

>

 

Whatever. It still has the "/V" switch, even if the switch is a no-op.

 

Then there's the placebo effect...

[Guest Pegasus \(MVP\)]

Re: Can I rely on "copy" command?

 

> Then there's the placebo effect...

>

 

ROFL!

[Guest LVTravel]

Re: Can I rely on "copy" command?

 

 

 

"Walter R." <wer25@example.com> wrote in message

news:ODFwzi3DJHA.5316@TK2MSFTNGP04.phx.gbl...

> I often have occasion to copy or move large blocks of files from one

> partition to another.

>

> Win XP SP2 has never told me yet that it has lost a byte here or a byte

> there. Can I assume that all transfers are done flawlessly and with zero

> data loss? Will Windows let me know if it accidentally loses or mangles a

> few bytes while transferring data?

>

> --

> Walter

> http://www.rationality.net

> -

>

 

While what others have said is true, there is one other issue with Copy. If

you use copy to copy a group of files with a wildcard and anything goes

wrong with the copy, it is automatically terminated at that point and

further files are not copied.

 

Xcopy does have a switch to ignore errors but that isn't a good feature in

the respect that you need to ensure a complete copy. Robocopy is better in

this respect.

 

There is another free program xxcopy.exe that will do what you want also.

It has a /v2 switch which will verify on a byte for byte basis that robocopy

won't. If you are using XXCopy in a corporate environment, there is a Pro

version that you can test drive for 60 days.

 

This is a biased report on the differences between Robocopy and XXCopy

http://www.xxcopy.com/xxcopy30.htm

 

For XXcopy download see: http://www.xxcopy.com/index.htm#download and click

#4 then download the .zip file.

 

I am not affiliated with the company in any way other than as a free user of

the software.

[Guest Patrick Keenan]

Re: Can I rely on "copy" command?

 

 

"Walter R." <wer25@example.com> wrote in message

news:ODFwzi3DJHA.5316@TK2MSFTNGP04.phx.gbl...

>I often have occasion to copy or move large blocks of files from one

>partition to another.

>

> Win XP SP2 has never told me yet that it has lost a byte here or a byte

> there. Can I assume that all transfers are done flawlessly and with zero

> data loss? Will Windows let me know if it accidentally loses or mangles a

> few bytes while transferring data?

 

Generally, the answer to this is "no". The copy command has a rather

annoying response to errors, which is to give up and exit. This leaves

you with no real idea of where or when the error occurred.

 

Better to use another copy utility that does not behave this way. Xcopy /v

is a good start, but I often use a program called FileSync that has a GUI,

keeps track of errors it encounters, and can do bit-by-bit comparisons of

large groups of files.

 

HTH

-pk

 

> --

> Walter

> http://www.rationality.net

> -

[Guest Bob I]

Re: Can I rely on "copy" command?

 

 

 

Pegasus (MVP) wrote:

> "Bob I" <birelan@yahoo.com> wrote in message

> news:%23OgTn83DJHA.4676@TK2MSFTNGP05.phx.gbl...

>

>>

>>Pegasus (MVP) wrote:

>>

>>

>>>"smlunatick" <yveslec@gmail.com> wrote in message

>>>news:dc32b5c6-2208-4f87-8116-4146a5ca69c3@y38g2000hsy.googlegroups.com...

>>>On Sep 5, 5:59 pm, "Walter R." <we...@example.com> wrote:

>>>

>>>

>>>>I often have occasion to copy or move large blocks of files from one

>>>>partition to another.

>>>>

>>>>Win XP SP2 has never told me yet that it has lost a byte here or a byte

>>>>there. Can I assume that all transfers are done flawlessly and with zero

>>>>data loss? Will Windows let me know if it accidentally loses or mangles a

>>>>few bytes while transferring data?

>>>>

>>>>--

>>>>Walterwww.rationality.net

>>>>-

>>>

>>>

>>>Nothing is every fool-proof. Xcopy has been around for some time and

>>>may be reliable.

>>>

>>>==============

>>>

>>>. . . and it has a /v (verify) switch!

>>

>>Don't bet on that.

>>

>>Using /v

>>Windows XP does not use this command. It is accepted only for

>>compatibility with MS-DOS files.

>>

>>and

>>

>>VERIFY ON, COPY /V, XCOPY /V Commands Do Not Compare Data

>>http://support.microsoft.com/kb/126457

>>

>

>

> Well, I learn something new every day! BTW, I assume you meant to write

> Windows XP does not use this switch instead of

> Windows XP does not use this command.

> because the command "xcopy.exe" is fully supported under WinXP (even though

> it is now deprecated in favour of robocopy).

>

>

 

I presume the "writer" of the Help file meant that, As I actually

copy/pasted directly from Windows Help and support. ;-) To see this

yourself, look up Xcopy in Help and Support, and click the Xcopy link,

scroll past the first "/v" that claims to compare file contents, and

look at first entry in the Remarks section. Also notice that the Exit

Error codes do not provide for any "file comparison error".

[Guest John John (MVP)]

Re: Can I rely on "copy" command?

 

Bob I wrote:

>

>

> Pegasus (MVP) wrote:

>

>> "Bob I" <birelan@yahoo.com> wrote in message

>> news:%23OgTn83DJHA.4676@TK2MSFTNGP05.phx.gbl...

>>

>>>

>>> Pegasus (MVP) wrote:

>>>

>>>

>>>> "smlunatick" <yveslec@gmail.com> wrote in message

>>>> news:dc32b5c6-2208-4f87-8116-4146a5ca69c3@y38g2000hsy.googlegroups.com...

>>>>

>>>> On Sep 5, 5:59 pm, "Walter R." <we...@example.com> wrote:

>>>>

>>>>

>>>>> I often have occasion to copy or move large blocks of files from one

>>>>> partition to another.

>>>>>

>>>>> Win XP SP2 has never told me yet that it has lost a byte here or a

>>>>> byte

>>>>> there. Can I assume that all transfers are done flawlessly and with

>>>>> zero

>>>>> data loss? Will Windows let me know if it accidentally loses or

>>>>> mangles a

>>>>> few bytes while transferring data?

>>>>>

>>>>> --

>>>>> Walterwww.rationality.net

>>>>> -

>>>>

>>>>

>>>>

>>>> Nothing is every fool-proof. Xcopy has been around for some time and

>>>> may be reliable.

>>>>

>>>> ==============

>>>>

>>>> . . . and it has a /v (verify) switch!

>>>

>>>

>>> Don't bet on that.

>>>

>>> Using /v

>>> Windows XP does not use this command. It is accepted only for

>>> compatibility with MS-DOS files.

>>>

>>> and

>>>

>>> VERIFY ON, COPY /V, XCOPY /V Commands Do Not Compare Data

>>> http://support.microsoft.com/kb/126457

>>>

>>

>>

>> Well, I learn something new every day! BTW, I assume you meant to write

>> Windows XP does not use this switch instead of

>> Windows XP does not use this command.

>> because the command "xcopy.exe" is fully supported under WinXP (even

>> though it is now deprecated in favour of robocopy).

>>

>

> I presume the "writer" of the Help file meant that, As I actually

> copy/pasted directly from Windows Help and support. ;-) To see this

> yourself, look up Xcopy in Help and Support, and click the Xcopy link,

> scroll past the first "/v" that claims to compare file contents, and

> look at first entry in the Remarks section. Also notice that the Exit

> Error codes do not provide for any "file comparison error".

 

Here on my antique still in use NT4 box it says:

 

/v

Verifies each file as it is written to the destination file to make sure

that the destination files are identical to the source files. This

switch is ignored because the functionality is inherent to the

Windows NT operating system. The switch is accepted only for

compatibility with previous versions of MS-DOS.

 

John

[Guest Bob I]

Re: Can I rely on "copy" command?

 

 

 

John John (MVP) wrote:

> Bob I wrote:

>

>>

>>

>> Pegasus (MVP) wrote:

>>

>>> "Bob I" <birelan@yahoo.com> wrote in message

>>> news:%23OgTn83DJHA.4676@TK2MSFTNGP05.phx.gbl...

>>>

>>>>

>>>> Pegasus (MVP) wrote:

>>>>

>>>>

>>>>> "smlunatick" <yveslec@gmail.com> wrote in message

>>>>> news:dc32b5c6-2208-4f87-8116-4146a5ca69c3@y38g2000hsy.googlegroups.com...

>>>>>

>>>>> On Sep 5, 5:59 pm, "Walter R." <we...@example.com> wrote:

>>>>>

>>>>>

>>>>>> I often have occasion to copy or move large blocks of files from one

>>>>>> partition to another.

>>>>>>

>>>>>> Win XP SP2 has never told me yet that it has lost a byte here or a

>>>>>> byte

>>>>>> there. Can I assume that all transfers are done flawlessly and

>>>>>> with zero

>>>>>> data loss? Will Windows let me know if it accidentally loses or

>>>>>> mangles a

>>>>>> few bytes while transferring data?

>>>>>>

>>>>>> --

>>>>>> Walterwww.rationality.net

>>>>>> -

>>>>>

>>>>>

>>>>>

>>>>>

>>>>> Nothing is every fool-proof. Xcopy has been around for some time and

>>>>> may be reliable.

>>>>>

>>>>> ==============

>>>>>

>>>>> . . . and it has a /v (verify) switch!

>>>>

>>>>

>>>>

>>>> Don't bet on that.

>>>>

>>>> Using /v

>>>> Windows XP does not use this command. It is accepted only for

>>>> compatibility with MS-DOS files.

>>>>

>>>> and

>>>>

>>>> VERIFY ON, COPY /V, XCOPY /V Commands Do Not Compare Data

>>>> http://support.microsoft.com/kb/126457

>>>>

>>>

>>>

>>> Well, I learn something new every day! BTW, I assume you meant to write

>>> Windows XP does not use this switch instead of

>>> Windows XP does not use this command.

>>> because the command "xcopy.exe" is fully supported under WinXP (even

>>> though it is now deprecated in favour of robocopy).

>>>

>>

>> I presume the "writer" of the Help file meant that, As I actually

>> copy/pasted directly from Windows Help and support. ;-) To see this

>> yourself, look up Xcopy in Help and Support, and click the Xcopy link,

>> scroll past the first "/v" that claims to compare file contents, and

>> look at first entry in the Remarks section. Also notice that the Exit

>> Error codes do not provide for any "file comparison error".

>

>

> Here on my antique still in use NT4 box it says:

>

> /v

> Verifies each file as it is written to the destination file to make sure

> that the destination files are identical to the source files. This

> switch is ignored because the functionality is inherent to the Windows

> NT operating system. The switch is accepted only for compatibility with

> previous versions of MS-DOS.

>

> John

>

 

Yes, one has to "trust" that Windows did what you told it to do, or

"check it yourself". ;-)