Bizzare network drive issues (yes, plural!)

[RevWaldo]

We're having an usual issue with MDB files on a network drive (which is
in a server in another building many blocks away, but we have fat pipes
and everything works fine otherwise.) Perhaps this rings a bell with
someone out there.

Some thumbnail background first. We're a fairly large company with
several offices in a big city (and many others in the US and worldwide)
and an extensive network of PC and servers. Our department moved from
an old office to the new office, and when we tried to use our little
Access database, which has front ends on the user's PCs an a back end
on the network drive - the same one we were connecting to at our old
office - "disk or network error" errors started to appear
intermittently when running queries or entering form data. I did some
investigating and narrowed it down to these symptoms. (Note the old
office was in a separate building from the network drive as well.)

When we copy an MDB file - a nice normal test file that contains only
one table and opens OK on the local drive - from a local C: drive to
the network drive either one of two things happen:

*** Result No. 1) The file begins to copy OK but it then stalls about
90% of the way there and eventually times out with a "File path too
deep" error, even though the path isn't anywhere near being too deep.
When you open the resulting MDB file on the network drive, MS Access
comes back with "The Microsoft Jet database engine stopped the process
because you and another user are attempting to change the same data at
the same time." Of course there isn't another user.

Note that files other than MDB files (PDF, XLS, etc.) copy over and
open OK. It happens to MDB files regardless of size (tried it with 3 MB
files and 16MB files, same thing.) And even *more* bizarre, if you try
to trick it by changing the MDB files extension to something else (like
from foobar.mdb to foobar.xxx) THE SAME THING HAPPENS - you get the
same "file path too deep" error and when you change the extension back
on the network copy and open it you get the same Microsoft Jet error.

*** Result No. 2) When we try copying from a local drive on a
*different* PC to the network drive, the file copies OK (at least it
appears OK.) When you try to open the network copy, the database object
window (the list of tables, queries, etc.) appears OK. So far so good!
But when we open the test table, it stalls and a "disk or network
error" appears. Again, this doesn't appear to be related to file size.

Does this ring any bells with anyone? I know result no. 2 is common
enough, but it's result no. 1 that's truly head-scratching. Our IT
Network folks and Windows folks have been punting this back and forth
with no resolution so far.

Thanks in Advance!

Chris O.

 

[Tony Toews]

We're having an usual issue with MDB files on a network drive (which is
in a server in another building many blocks away, but we have fat pipes
and everything works fine otherwise.)

Define fat pipes. 10 mpbs? 100 mpbs? What differences are there
between your old and new office.

Some thumbnail background first. We're a fairly large company with
several offices in a big city (and many others in the US and worldwide)
and an extensive network of PC and servers. Our department moved from
an old office to the new office, and when we tried to use our little
Access database, which has front ends on the user's PCs an a back end
on the network drive - the same one we were connecting to at our old
office -

So the same PCs at your new office and the same server at the remote
location?

narrowed it down to these symptoms.

Very nice set of trouble shooting and description of the problems. I
wish more people would post detail like this.

When we copy an MDB file - a nice normal test file that contains only
one table and opens OK on the local drive - from a local C: drive to
the network drive either one of two things happen:

How large a file? 64 kb? 20 mb?

And even *more* bizarre, if you try
to trick it by changing the MDB files extension to something else (like
from foobar.mdb to foobar.xxx) THE SAME THING HAPPENS - you get the
same "file path too deep" error and when you change the extension back
on the network copy and open it you get the same Microsoft Jet error.

Now what do you mean by same Jet Error? The Stopped the Process
message?

Note that files other than MDB files (PDF, XLS, etc.) copy over and
open OK. It happens to MDB files regardless of size (tried it with 3 MB
files and 16MB files, same thing.)

What about PDF or XLS files that are also 3 Mb or 16 Mb?

*** Result No. 2) When we try copying from a local drive on a
*different* PC to the network drive, the file copies OK (at least it
appears OK.) When you try to open the network copy, the database object
window (the list of tables, queries, etc.) appears OK. So far so good!
But when we open the test table, it stalls and a "disk or network
error" appears. Again, this doesn't appear to be related to file size.

Another way of troubleshouting would be to create a 10, 20 or 100 mb
Zipped file. Copy it to the server. Copy it back. Then run the test
function within Winzip. If it tests ok then I dunno. If it tests bad
then it's a network problem. And nothing to do with Access.

Tony
--
Tony Toews, Microsoft Access MVP
Please respond only in the newsgroups so that others can
read the entire thread of messages.
Microsoft Access Links, Hints, Tips & Accounting Systems at
http://www.granite.ab.ca/accsmstr.htm

 

[RevWaldo]

Define fat pipes. 10 mpbs? 100 mpbs? What differences are there
between your old and new office.

First some obvious left-out info: Access 2003, Windows XP SP2
The LANs in our building and the one with the server are connected by a
T3 line.

So the same PCs at your new office and the same server at the remote
location?

Newer ones, actually - Dell OptiPlex GX620s - Pentium 4 3.00MHz, 512MB

Very nice set of trouble shooting and description of the problems. I
wish more people would post detail like this.

Thanks! (Been down this road far too many times.)

How large a file? 64 kb? 20 mb?

I tested with 16MB and 4 MB files - both flunked.

Now what do you mean by same Jet Error? The Stopped the Process
message?
Yep.


What about PDF or XLS files that are also 3 Mb or 16 Mb?

I tested with 16MB PDF and XLS files. Ran perfectly.

Another way of troubleshouting would be to create a 10, 20 or 100 mb
Zipped file. Copy it to the server. Copy it back. Then run the test
function within Winzip. If it tests ok then I dunno. If it tests bad
then it's a network problem. And nothing to do with Access.

Worth a try, I'll post the results. My main wonder is why MDB files
would be treated differently by the OS during copying. The way the
files are structured or encoded, maybe?

Chris O.

 

[Tony Toews]

First some obvious left-out info: Access 2003, Windows XP SP2
The LANs in our building and the one with the server are connected by a
T3 line.

I'm not at all sure what a T3 line is. What was your old connection.

Newer ones, actually - Dell OptiPlex GX620s - Pentium 4 3.00MHz, 512MB

So it's possible then that some of the new PCs could have slightly
defective network cards, etc, etc. I'd suggest uploading and
downloading a 10 or 20 Mb Zip file from each just to see if that is a
factor.

Thanks! (Been down this road far too many times.)


I tested with 16MB and 4 MB files - both flunked.
Ok.


I tested with 16MB PDF and XLS files. Ran perfectly.

Now that is bizarre. I'm also wondering if your new machines have
different anti-virus software or different anti virus settings.
Norton in particular seems to have some problems with MDBs.

Can you see if you can exclude MDBs from the virus scanning process.

Worth a try, I'll post the results.

Please do. Also email me at tony at granite dot ab doc ca when you
post something to the newsgroup. I'll also respond in the newsgroup
as I want all postings to be publicly accessible.

My main wonder is why MDB files
would be treated differently by the OS during copying. The way the
files are structured or encoded, maybe?

You would think it wouldn't make any difference. Which is why I
mentioned the antivirus software. After all a byte is a byte. No
matter if it's a pdf, zip or mdb file.

Just for grins. Take that 10 Mb zip file, rename it to an MDB
extension, copy it up to the server and down again, and see if there's
any difference in behavior.

And why, yes, I do enjoy interesting problems like yours. Of course
I can treat them with some intellectual disdain as I don't have to
deal them with first hand. Kinda like grand parents who retain a
toddler when the diaper needs changing. <smile>

Tony
--
Tony Toews, Microsoft Access MVP
Please respond only in the newsgroups so that others can
read the entire thread of messages.
Microsoft Access Links, Hints, Tips & Accounting Systems at
http://www.granite.ab.ca/accsmstr.htm

 

[david epsom dot com dot au]

Worth a try, I'll post the results. My main wonder is why MDB files
would be treated differently by the OS during copying. The way the
files are structured or encoded, maybe?

Chris O.

Sounds like a security problem to me - virus scanning or even
that strange security thing that marks files if they are
'downloaded from the internet.'

Also check to see if you are using a compressed drive -
compression happens in the background, so copy/move
works differently, and an MDB might compress differently
from a pdf/xls.


(david)

 

[RevWaldo]

I'm not at all sure what a T3 line is. What was your old connection.

(Sorry for the delayed reply.) It's the same as a DS3 line - 45 MBps.
Our old connection was similar.

So it's possible then that some of the new PCs could have slightly
defective network cards, etc, etc. I'd suggest uploading and
downloading a 10 or 20 Mb Zip file from each just to see if that is a
factor.

Zip files move around OK. I can copy from local to network and back
again, and they unpack fine. As expected, trying to unzip a zipped MDB
file to the network drive doesn't work.

Now that is bizarre. I'm also wondering if your new machines have
different anti-virus software or different anti virus settings.
Norton in particular seems to have some problems with MDBs.

Can you see if you can exclude MDBs from the virus scanning process.

Possibly, I'll mention it to support, although we have the same virus
protection at our old location (Symantec) at it worked fine.

Tried this with a 35 MB zip file (113 MB of files - five MDB files, one
PDF, one XLS) and it tested OK.

Please do. Also email me at tony at granite dot ab doc ca when you
post something to the newsgroup. I'll also respond in the newsgroup
as I want all postings to be publicly accessible.


You would think it wouldn't make any difference. Which is why I
mentioned the antivirus software. After all a byte is a byte. No
matter if it's a pdf, zip or mdb file.

Just for grins. Take that 10 Mb zip file, rename it to an MDB
extension, copy it up to the server and down again, and see if there's
any difference in behavior.

I tried this with the same 35 MB zip file, and it copied back and forth
OK.

And why, yes, I do enjoy interesting problems like yours. Of course
I can treat them with some intellectual disdain as I don't have to
deal them with first hand. Kinda like grand parents who retain a
toddler when the diaper needs changing. <smile>

Thanks again,

Chris O.

 

[Tony Toews]

(Sorry for the delayed reply.) It's the same as a DS3 line - 45 MBps.
Our old connection was similar.

Umm, yeah, but how similar? Although I don't think that's the problem
from your next paragraphs.

Zip files move around OK. I can copy from local to network and back
again, and they unpack fine.

Ok, then I doubt it's the network. I'd sure be eyeing the anti-virus
scanner.

Oh, what happens when you rename an MDB file to another extension and
copy it back and forth on the network.

As expected, trying to unzip a zipped MDB
file to the network drive doesn't work.

Not sure what you're trying to tell me here.

Possibly, I'll mention it to support, although we have the same virus
protection at our old location (Symantec) at it worked fine.

But new computers could have a configuration change. Is the server
the same?

Tried this with a 35 MB zip file (113 MB of files - five MDB files, one
PDF, one XLS) and it tested OK.

Ok, so it;s very unlikely to be the network itself.

I tried this with the same 35 MB zip file, and it copied back and forth
OK.

Ok, Now I strongly suspect an antivirus scanner is smart enough to
ignore the extension and figure out what kind of file from the first
bytes in the file.

Whoops, that didn't come out right. Grandparents who give back a
toddler when the diaper needs changing.

Tony
--
Tony Toews, Microsoft Access MVP
Please respond only in the newsgroups so that others can
read the entire thread of messages.
Microsoft Access Links, Hints, Tips & Accounting Systems at
http://www.granite.ab.ca/accsmstr.htm

 

[larryking]

www.pathtoodeep.com fixes that problem