Re: Reliability of files copied via Windows Explorer

"TE" <> wrote in message
news:ea9a4dcc-3035-43c5-afab-...

> I plan to copy about 20 1GB files (occasionally) from a Windows XP
> laptop to a Windows XP desktop using Windows Explorer across a
> wireless network (802.11g)
> Is there a possibility that the files could get corrupted during
> transfer?
> Is there anything in Windows Explorer (a protocol maybe?) that ensures
> that the files do not get corrupted during the transfer?

There is always the chance of corruption (because cosmic ray
particles are constantly passing through your body and your PC):
but Windows Copy and Move functions have parameters to
verify integrity of a Copied or Moved file.

> An alternative would be for me to use .zip files and check the archive
> integrity of the .zip files on the desktop after the transfer

The simplest way would be to connect the two computers
via their NIC jacks and just copy the files over.
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

On Wed, 5 Nov 2008 10:08:45 -0500, "Don Phillipson"
<> wrote:

>"TE" <> wrote in message
>news:ea9a4dcc-3035-43c5-afab-...
>
>> I plan to copy about 20 1GB files (occasionally) from a Windows XP
>> laptop to a Windows XP desktop using Windows Explorer across a
>> wireless network (802.11g)
>> Is there a possibility that the files could get corrupted during
>> transfer?
>> Is there anything in Windows Explorer (a protocol maybe?) that ensures
>> that the files do not get corrupted during the transfer?
>
>There is always the chance of corruption (because cosmic ray
>particles are constantly passing through your body and your PC):
>but Windows Copy and Move functions have parameters to
>verify integrity of a Copied or Moved file.
>
>> An alternative would be for me to use .zip files and check the archive
>> integrity of the .zip files on the desktop after the transfer
>
>The simplest way would be to connect the two computers
>via their NIC jacks and just copy the files over.

That's the way I copy. And even then, files get lost or
corrupted. Don't expect wiresless to be more reliable !

I run MD5 checks and do directory compares between source and
destination.
- Files get lost during a copy operation. Sometimes for a
traceable reason, sometimes without visible reason.

- Files get corrupted during a copy operation. Mostly because of
a hickup during the copy action. (E.g. pull an external drive's
USB plug.) Or maybe due to your cosmic rays :-)

My rule of thumb: the file is only there if you have verified
that it is :-)
(And it is only then verified if the crc32 or MD5 matches!)

By the way: did the OP calculate how long his 20 GB wireless
transfer is going to take ?

--
Kind regards,
Gerard Bok

On Thu, 6 Nov 2008 22:20:55 -0800 (PST), TE <>
wrote:

>On Nov 6, 4:06=A0am, bok...@zonnet.nl (Gerard Bok) wrote:
>> By the way: did the OP calculate how long his 20 GB wireless
>> transfer is going to take ?
>
>For 24GB of files, I think Windows Explorer initially reported about
>186 minutes.
>But Explorer is known to be highly inaccurate about these times and
>the speed does fluctuate based on ???
>
>I also notice that when I turn on the microwave oven, streaming video
>over 802.11g from my desktop to my laptop is affected.
>Could a file transfer be affected too?

802.11 communication speeds depend on the environment.
A microwave may affect speed.
As may your neighbour's use of their wireless network or their
baby-watch cam.
Even a person, walking between the AP and your laptop may
influence speed :-)

So from a (far) distance, there is no way of predicting either
the speed or the reliablility of your transfer.

There is also an issue of filesize. If the 24 GB is in one solid
file, any transmission problem will require that entire file to
be retransmitted :-)


--
Kind regards,
Gerard Bok

Gerard Bok wrote:

> There is also an issue of filesize. If the 24 GB is in one solid
> file, any transmission problem will require that entire file to
> be retransmitted :-)

Which is one of the reasons why Robocopy is the utility of choice for
copying large files accross a network, it can pickup where it left off
when the outage occured, it doesn't need to start all over just because
the last 10 bytes of a 24GB file are missing!

John