What happens to DWG files when they are saved?

[patrick.greg252789]

Hi Folks,

We are looking at using DFS-R for data replication of DWG drawing files across our WAN to a number of servers and a pertinent question was asked that I was unable to immediately answer. I'm hoping someone here will be able to answer that question for me.

What happens to a DWG file when it is saved? Does it change at the block level only to identify a difference in the file, or is the file completely re-written?

If it is only changed at the block level of the file this means DFS-R only has to move the changed portion of the file, but if it re-writes the entire file, then it has to move the entire file again.

Any assistance in answering this would be greatly appreciated!

[cadtag]

My understanding is that a save creates a new file, based on the drawing information in local memory with a temporary name, If that is successful, the existing .dwg is renamed to .bak and the newly created file is renamed to the original file name with the .dwg extension.

[jpaulsen]

The file is mostly re-written. See this somewhat related thread.
http://forums.autodesk.com/t5/AutoCAD-Civil-3D/Civil-3D-drawings-and-Riverbed-WAN-accelerators/td-p/3368853 (http://forums.autodesk.com/t5/AutoCAD-Civil-3D/Civil-3D-drawings-and-Riverbed-WAN-accelerators/td-p/3368853)