This posting refers to failures in saving AutoCAD files and the increasing
presence of temporary files, ATMP#### (i.e. ATMP1234), that should not be
left after a successful save. In some cases, the CAD user ends up with a
complete DWG file, including changes. In other cases, the DWG is completely
missing. I logged a support call with AutoCAD, Case No. 1034177, and found
that the errors my company are experiencing have plagued AutoCAD for many
versions, without a successful resolution. After I heard this, I ran a dir
/s /u ATMP* on 4 or 5 of our servers and found that we have close to 1,000
ATMP#### files, by an assortment of users. The list includes files created
by AutoCAD 2002/2004 and earlier, Architectural Desktop 2002/2004 and Land
Development.
My staff installed a diagnostic program, Filemon, and used it to track what
AutoCAD 2002 does when a file is saved. AutoCAD 2004 seems to be similar. We
captured file activity from the Save and came up with the following process.
In this process, all of the files were created in folders on the drive
letter that the file was opened on. So, for example, if the file was opened
on D:\temp, all of the files mentioned in the process steps would be in
D:\temp.
1. The user runs File-Save or Qsave
2. Autocad checks for the existance of a file Save.ac$. If a file of this
name does not exist, AutoCAD will save your AutoCAD work to Save.ac$,
starting in Step 4.
3. If Save.AC$ exists, then AutoCAD determines a file to use that is unique
and has the format Sav###.ac$. For example Sav123.ac$. If you are using
AutoCAD 2004, the file seems to take the format of Sav123.tmp.
4. AutoCAD then looks for a Sav###.dwk file. This is apparently done to
support previous versions of AutoCAD since the dwk file locking is not used
in 2002/2004. If the file is found, it would probably generate a Read-Only
message since the file would indicate that someone has the file locked using
an older version of AutoCAD. In our case, no dwk files would be found.
5. AutoCAD writes all of your CAD changes from memory to the filename
Save.ac$, Sav123.ac$ or Sav123.tmp. This file will eventually be your dwg
file with revisions.
6. The original dwg file is renamed to Atmp####, for example Atmp1234 (no
extension).
7. If a bak file existing when you started, it is deleted in this step.
8. The Atmp1234 file is renamed to Filename.bak
9. The Save.ac$, Sav123.ac$ or Sav123.tmp is renamed to Filename.dwg. This
is your saved dwg file.
10. The Filename.dwg file is opened
One of our techs was losing his dwg files. But, the Sav###.ac$ file existed
as well as the Atmp### file. So his process was crashing about Step 8. This
happened if he saved his drawing on a network drive or on his local D:
drive. I have two other users that have lost dwg files in a similar fashion.
I have hundreds of others that left Atmp#### files, but did not lose their
dwg file. I am not sure why this is. Sometimes, a message is generated:
***Unable to save to drawing D:\Temp\Test01.dwg
Drawing saved to D:\Temp\Sav216.tmp***(see attachment, this is from 2004)
This message is not always generated. It looks like that closing AutoCAD or
the drawing, and saving when it asks, may fail sometimes and not generate
the message.
When I discussed this with Autodesk, they have been aware of this problem
for some time. They have had Microsoft examine their code. They claim that
Microsoft declared their code sound. My evidence shows that this is not
true. So Autodesk has blamed slow computers, too fast computers, servers,
using CAD files over a WAN-speed connection, Windows (losing lock requests)
and such. All of these put the blame on the local hardware, software or
network. Since a lot of file re-naming is involved, Windows must lose some
of them due to timing issues. Probably Microsoft needs to fix something or
explain the solution to Autodesk. I suggested that Autodesk change their
code to detect the failure and then give the user a chance to try again. The
tech support person told me they were worried about tinkering with the
code - that they could make things worse.
I am concerned that we are getting 800 of the Atmp### files per month. This
started in late April 2004. Prior to this, we have some, but not nearly so
many. In April, May and June, we converted our servers to Windows Server
2003. We also changed our domain name and instigated Shadow Copy. We
speculate that Shadow Copy may aggravate this problem, but it is only a
theory.
My next step is to log a call with Microsoft support. If anyone has
additional information, please post it. I will do the same.