vanishing drawing

[cadtag]

Here's a fun one - which fortunately was caught in time, but next time may not be noticed. It's the second time this has happened, and no one seems to have a good idea of the cause.

While working in a drawing on the server with four layout tabs assigned to the sheet set, I made a minor text edit, did a QSave, and then opened a different file from SSM. Several minutes later, I noticed that the SSM windows was showing ?'s over the drawing icons for the sheets in the file I had just saved. Double-clicking the icon for one of those sheets gave me an alert that the dwg associated with the sheet could not be found.

I dropped back to Windows Explorer, and browsed to the correct folder, and sure enough the dwg file did NOT show up. The only .bak file for that drawing had a date of March 5 - although I have been in and out of that project and that design file repeatedly over the past few weeks.

To make it more interesting, that folder, uniquely among every other project folder on the server, had 20+ .tmp files, along with the expected dwg and other extensions. the .dwl and .dwl2 files for the missing dwg were still there, and the dwg was still open in the active Acad session, but the dwg file no longer existed.

I did verify that no one else with access to that project folder had been doing anything with that project, so the idea of someone else deleting the file has been rejected.

Nothing relevant showed up in the server event logs.. ITS will run a chkdsk on the server this evening as a precaution (primarily because of the huge number of tmp files in that folder) but no-one in house has a reasonable idea of the cause.

Thoughts?

[rkmcswain]

IIRC- when you save a drawing, AutoCAD writes the contents of the editor to a TMP file, then when that is complete, it copies the current DWG to a BAK file (if this option is enabled), and then finally, it renames the TMP file to the correct DWG file.

Maybe this process is being interfered with by the server, and the last step is never occurring?

[cadtag]

Yeah,, something is interfering. the insanely frustrating part is that the failure to save did not give me any alerts, and evidently this has been going on with that folder for a while -- since the only .bak was dated in March rather than last week. but the dwg was current with changes from the last couple of edits in it.

Steps we've learned from Adesk are: (positing an open drawing named TEST)


1) Saves current open file to SAV341.TMP (random number each time, but begins with SAV and ends with .TMP always)

2) Rename existing TEST.DWG to ATMP6334 (no file extension, always begins with ATMP)

3) Delete TEST.BAK if it exists

4) Rename ATMP6334 to TEST.BAK

5) Rename SAV341.TMP to TEST.DWG



There were both SAV###.TMP and ATMP###. files in that folder, all roughly the right size, and with dates going back to April. The .bak file was Read-only - (no good reason for that, and probably a big part of the problem).

[rkmcswain]

Yeah,, something is interfering. the insanely frustrating part is that the failure to save did not give me any alerts, and evidently this has been going on with that folder for a while -- since the only .bak was dated in March rather than last week. but the dwg was current with changes from the last couple of edits in it.

Steps we've learned from Adesk are: (positing an open drawing named TEST)


1) Saves current open file to SAV341.TMP (random number each time, but begins with SAV and ends with .TMP always)

2) Rename existing TEST.DWG to ATMP6334 (no file extension, always begins with ATMP)

3) Delete TEST.BAK if it exists

4) Rename ATMP6334 to TEST.BAK

5) Rename SAV341.TMP to TEST.DWG



There were both SAV###.TMP and ATMP###. files in that folder, all roughly the right size, and with dates going back to April. The .bak file was Read-only - (no good reason for that, and probably a big part of the problem).

Cool. Now the part I've always wondered about.... the "rename" function. Does this involve moving bits on disc or not? IOW - is a "rename" really a copy & delete?

Why does it matter? If the O/S has to open the file for WRITE (to rename it) and the operation fails due to a power outage for example, the file could be lost. If a rename operation is really doing a copy & delete, then the chances for data loss go way down...

[cadtag]

Cool. Now the part I've always wondered about.... the "rename" function. Does this involve moving bits on disc or not? IOW - is a "rename" really a copy & delete?

Why does it matter? If the O/S has to open the file for WRITE (to rename it) and the operation fails due to a power outage for example, the file could be lost. If a rename operation is really doing a copy & delete, then the chances for data loss go way down...

My presumption (and that's all it is) is that it's a RENAME, not a copy. And that would be due to performance considerations. A rename action just needs to modify the file allocation table on disk and not duplicate a potentially megabyte file. that multi-step process with SAV###.TMP and ATMP### should prevent loss of data in theory (but as I know it's not foolproof.

Might be interesting to monitor the steps w/ procmon or filemon now that we know what to look for. To make it really fun, set the .bak to ReadOnly first.

[gfreddog]

Here's a fun one - which fortunately was caught in time, but next time may not be noticed. It's the second time this has happened, and no one seems to have a good idea of the cause.

While working in a drawing on the server with four layout tabs assigned to the sheet set, I made a minor text edit, did a QSave, and then opened a different file from SSM. Several minutes later, I noticed that the SSM windows was showing ?'s over the drawing icons for the sheets in the file I had just saved. Double-clicking the icon for one of those sheets gave me an alert that the dwg associated with the sheet could not be found.

I dropped back to Windows Explorer, and browsed to the correct folder, and sure enough the dwg file did NOT show up. The only .bak file for that drawing had a date of March 5 - although I have been in and out of that project and that design file repeatedly over the past few weeks.

To make it more interesting, that folder, uniquely among every other project folder on the server, had 20+ .tmp files, along with the expected dwg and other extensions. the .dwl and .dwl2 files for the missing dwg were still there, and the dwg was still open in the active Acad session, but the dwg file no longer existed.

I did verify that no one else with access to that project folder had been doing anything with that project, so the idea of someone else deleting the file has been rejected.

Nothing relevant showed up in the server event logs.. ITS will run a chkdsk on the server this evening as a precaution (primarily because of the huge number of tmp files in that folder) but no-one in house has a reasonable idea of the cause.

Thoughts?

Having the same issue with one project. Not using SSM though. A user worked on 3 drawings saved and closed. Reopens later and they are yesterday's versions. And no BAK file has been saved.

Ideas?

[cadtag]

I think that my original problem was caused by the .BAK being read-only, can you verify that the user can create and delete files in that folder?

[gfreddog]

I think that my original problem was caused by the .BAK being read-only, can you verify that the user can create and delete files in that folder?

Yes they can read and write to it. The .BAK's are not read only. His software didn't save or create a new . BAK.

Upon restart all worked fine for new saves. But the old files are missing ugh.