The Autosave Mystery

There seems to be a lot of confusion and misinformation out there regarding the operation of AutoCAD’s automatic save function. First and foremost, it is not a replacement for the QSAVE command. AutoCAD’s automatic save simply writes a copy of the current drawing to disk every so often, and when you shutdown AutoCAD normally, those file(s) are deleted.
Let me repeat that: When you shutdown AutoCAD normally, the autosave files are DELETED!

Here is more or less a rundown of what occurs:

  • As soon as a new drawing is modified (in other words, when DBMOD does not equal 0), a timer starts.
  • When this timer reaches the value of the SAVETIME system variable, the automatic save function fires, an autosave file is created, and the timer is reset.
  • The autosave file is created in the directory defined by the SAVEFILEPATH system variable. File naming syntax is described below.
  • The timer is also reset anytime QSAVE, SAVE, or SAVEAS is executed.

Naming of the autosave file The autosave file is named using this syntax: drawing name_AutoCAD session number_MDE Window number_random$ …where

  • drawing name = the original drawing name.
  • AutoCAD session number = a number generated sequentially regarding concurrent sessions of AutoCAD.
  • MDE Window number = a number generated sequentially regarding concurrent open drawings in each session.
  • random number = a random number
  • .sv$ = this is always the file extension for autosave files.

A typical autosave file name might be:$ Sometimes AutoCAD may ‘crash’, but the autosave files are deleted anyway. I have seen this after AutoCAD generates a fatal error and you get the dialog that says “AutoCAD can not continue, do you want to save changes?” – in this case, AutoCAD is giving you a chance to save your changes (although I recommend saying NO in this case – we’ll save that story for another day…) Anyway, in the above case, the autosave file(s) will be deleted. Autosave files can be used by renaming them from .SV$ to .DWG. AutoCAD 2006 users get a new GUI called the “Drawing Recovery Manager” – now you don’t have to search for and manually rename files anymore.

One more TIP: If you want to RETAIN all autosave files regardless of whether you crash or not. Set up a directory with WRITE rights, but without DELETE rights. Use this as your SAVEFILEPATH. The autosave files will get written to this directory, but will not be deleted. Be sure to log in as a user with delete rights ever so often and clean out this directory.

Also, always make sure ISAVEPERCENT is set to zero (0).

Moral of the story: QSAVE OFTEN

1 Comment

  1. John W Dickinson (Post author)

    I set my autosave location to a folder that is backed up to my Google Drive. If I accidentally close a drawing without saving the changes (which I did this morning), the autosave file is backed up to Google Drive. I can then go into the trash on my Google Drive and restore the deleted *.SV$ file. That file will be redownloaded to the autosave location. I can then rename it to *.DWG and open it. I have found a way to protect me from myself!

    P.S. I set my autosave to 1 minute.


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