Reliability of files copied via Windows Explorer

[TE]

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?

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

 

[Don Phillipson]

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.

 

[John John (MVP)]

I recommend that you use Robocopy to do this, look for it on the
Microsoft site.

John

 

[Big_Al]

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?

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

Xcopy has a /V (verify new files) switch. Can't vouch for it.

I'll be interested to hear more input as I do the same thing. So I
copy all my digital photos and music monthly. I don't do more than
right click folders and do properties on both source and destination to
verify the file and byte counts. I might be about to fall into a
pit, but with 120 gigs of photos and music and software over 6 years,
I've been fine so far.

I've found http://msdn.microsoft.com/en-us/library/aa366778.aspx this
little utility that I use a lot. Not for the laptop to desktop thing,
but for making backups from desktop to external HD. I'm not about to
abandon 6 years of data that easily. It might be a bit heavy of
traffic to use over a network, but I'm not sure how paranoid you are.

There are other sync applications too that are around. Synctoy from MS
is another.

 

[John John (MVP)]

Xcopy has a /V (verify new files) switch. Can't vouch for it.

I'll be interested to hear more input as I do the same thing. So I
copy all my digital photos and music monthly. I don't do more than
right click folders and do properties on both source and destination to
verify the file and byte counts. I might be about to fall into a
pit, but with 120 gigs of photos and music and software over 6 years,
I've been fine so far.

I've found http://msdn.microsoft.com/en-us/library/aa366778.aspx this
little utility that I use a lot. Not for the laptop to desktop thing,
but for making backups from desktop to external HD. I'm not about to
abandon 6 years of data that easily. It might be a bit heavy of
traffic to use over a network, but I'm not sure how paranoid you are.

There are other sync applications too that are around. Synctoy from MS
is another.

The xcopy /v switch is ignored on NT operating systems.

John

 

[John John (MVP)]

Just curious as to why Robocopy would be more reliable than
just using Windows Explorer.
I can't figure out why it would make a difference???

It is the tool of choice for copying large files or a large number of
files across a network, it is just designed to handle this better than
xcopy ot the Windows GUI, see here for some of the differences with the
other tools: http://en.wikipedia.org/wiki/Robocopy

John

 

[philo]

It is the tool of choice for copying large files or a large number of
files across a network, it is just designed to handle this better than
xcopy ot the Windows GUI, see here for some of the differences with the
other tools: http://en.wikipedia.org/wiki/Robocopy

John

Thank you!

I guess I am a bit behind the times here.

The newest addition to my machine is the Windows 2000 support tools !


Guess I'll head over to the MS site and see for myself.

 

[Gerard Bok]

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.


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 ?

 

[Touch Base]

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?

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

==========================================
Karens Replicator v3.6.4
Automatically backup files, directories, even entire drives! Karen's
Replicator copies selected files from one drive/folder to another. Source
and Destination folders can reside anywhere on your network.

Options include repeated copies at intervals as short as a few minutes, or
as long as several months, copy only files that have changed, and the
replication of folder and file deletions.

http://www.karenware.com/powertools/ptreplicator.asp


--
Regards,
Touch Base
Report back on the results, good or bad so others may benefit

"There's an old story about the person who wished his computer were as easy
to use as his telephone. That wish has come true, since I no longer know
how to use my telephone."
(Bjarne Stroustrup)

 

[usasma]

I copy about 5 gB from my wife's office on a daily basis - and each time
(about 20 times altogether) that we restore the data it's worked properly.

- John

 

[TE]

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?

 

[Thumain Th.]

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?

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

==========================================
Karens Replicator v3.6.4
Automatically backup files, directories, even entire drives! Karen's
Replicator copies selected files from one drive/folder to another. Source
and Destination folders can reside anywhere on your network.

Options include repeated copies at intervals as short as a few minutes,
or
as long as several months, copy only files that have changed, and the
replication of folder and file deletions.

http://www.karenware.com/powertools/ptreplicator.asp

Same idea: Cobian backup , syncback

 

[Ken Blake]

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?

Possibility? Sure. There is always a possibility that something can go
wrong. But the likelihood of such a problem is extremely low.

If I were in your shoes (which I've been in many times) I would just do it
and I wouldn't worry about it at all.

 

[Gerard Bok]

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

 

[John John (MVP)]

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