AutoCAD Based Products File Save Process Explained in Detail

During a save here are all the steps that occur.  If any of these are interrupted, the process will fail and will give unusual errors, or cause slow behaviors. 

In this example, the AutoCAD Temporary Drawing Location is set to C:\ACAD Save 

Drawing named Test DWG.dwg is located here: D:\Downloads\Test DWG 

Some of these steps may occur without you ever seeing them (they are nearly instantaneous).

1. Standard QSAVE (occurs regardless of ISAVEPERCENT setting) command is triggered (or SaveAs)
    
2. Drawing save is initiated
   
   
3. Test DWG.DWG in RAM is written out to a .tmp first to the Temporary Drawing Location (briefly – you may not see this step as it’s near instantaneous)
   
   
    
4. Or the last Autosave (sv$ extension), if it’s enabled and has triggered at least once, is removed and renamed as a .tmp and the rest of the save process continues
    
5. Then that .TMP file is moved to the destination location
   
    

4. Test DWG.BAK is renamed to a temp file with no extension 
    
5. Test DWG.DWL & Test DWG.DWL2 are deleted (to allow modification to the Test DWG.dwg)
    
6. Test DWG.DWG renamed to Test DWG.BAK

7. Temp file with no extension is deleted
    
8. The .TMP renamed to Test DWG.DWG
   
    

9. Test DWG.DWL & Test DWG.DWL2 are re-created (to lock the Test DWG.dwg again)
    
10. Test DWG.dwg remains in RAM on the local machine for current session.
     
11. Test DWG.DWL & Test DWG.DWL2 remain as-is (until user closes Test DWG.Ddwg, at which time they are deleted).