Multiple users are able to open the same AutoCAD dwg file.

[Anonymous]

We are having a issue where two users can open up the same DWG file at the same time, both can edit and save the drawing file.  The DWG files are on the local server and AutoCAD is installed on each workstation.  Any idea on what might be causing this?

[JDMather]

You don't indicate if you are using Vault.

[Anonymous]

We are not using vault

[DarrenP]

is it possible that the file is saved in 2 different directories and saved as the same file name

[HawkAIA]

We are having the same issue.  Not using Vault.  The file is on the server in only one directory.  This was a problem in an earlier version of Autocad for Mac but was fixed.  Looks like it has migrated to Windows version.

[Anonymous]

Did you ever figure this out? We are having the same issue and we are losing a lot of work because of it.

Thanks in advance!

[rkmcswain]

Did something change recently?

New server?

New network?

Or did this just start happening one day out of the blue?

[Anonymous]

We did update our server a few months ago but this just started happening 2
weeks ago. Unfortunately I don't know much about the server details to
provide any more info.

[rkmcswain]

Are your IS/IT people involved? I've seen things like this happen when a non-compliant server O/S was not being used. Same thing for a SAN/NAS setup. File locking is done by the server O/S, so it sounds like something is going on there.

[Anonymous]

Thank you, I will make sure our IT people get involved with the issue.

--
*Jamie Pagliaroli *
914.494.7659

[HawkAIA]

No, we still have the problem.  The latest theory is that this has something to do with newer server software that is running "File Versioning" services.  On newer Mac/Unix servers for example, this allows files to be saved without hitting a "save" button.  It is software specific - not all software takes advantage of the service  One idea is to go into each client and turn off the file versioning service on the client machines.   We have not tried it yet, as I'm skeptical of that solution.

Our current solution is to make people actually talk to each other about files they have open at the same time, but we are all in one studio within shouting distance of each other.

[rkmcswain]

I can't tell you the specifics with all the technical lingo, but I can tell you that here, we had to back it all down to a Windows Server based O/S in order to get these problems to go away. Evidently, Autodesk does some tricky/fancy stuff during i/o that only Windows API understands

Our main problem was not that two people could get R/W access to a drawing, but they we would open a drawing, make changes, save it, then re-open it and the changes were not there.

[HawkAIA]

Our current thought is that we have a conflict between Open Directory on some servers and Active Directory on the Windows servers, so we are in the process of reconfiguring our directory services to all point to AD, and turn off OD.  We have several Mac users using Autocad on Parallels, so I'm thinking that the issue might be caused by directory services conflicts.  Once we get that done, I'll let you know if that solves the problem for us.

Interesting about the Windows API calls.  Could be bad news for my 12 TB RAID6 SAN, if that is the case.  Personally, I think a lot of this stuff is close to reaching the Software Peter Principle.

[HawkAIA]

It took a while (years), but I finally isolated the issue in our office.  After installing a new Windows 2012 file server and still having the same problem with mutiple users being able to open the same file at the same time, I did some testing with Autocad for Mac 2015, and Windows Autocad 2016 and found the following:

1.)  If two users are connected to any of our servers (Mac Server or Windows 2012 server) via Windows networking, and one tries to open a file residing on the server that is already in use by the other, the user will receive a proper notification dialog box asking if the user wishes the file to be opened as read only.

2.)  If one of the above two users is on a Mac using Autocad for Mac, the message will change to "The file is Invalid," but the ops-lock still works.

3.)  If a user connected via Windows networking or Mac SMB has the file residing on the server open, and a user with Windows Autocad 2016 running in Parallels in Shared networking mode tries to open the same file, the Parallels user will receive a dialog box message that the file is invalid, but the .dwl file lock still works.

4.) If a user connected via Parallels bridged mode has the file residing on the server open and an Autocad for Mac user tries to open the file, the AfM user will receive a dialog box message that the file is invalid, but the .dwl file lock still works. 

5.) If both users are connected via Parallels shared folders (.psf) via Shared network connection on Parallels, both users will be able to open the file.  Last one to save is the winner.  The .dwl file lock is apparently ignored by the virtual network adapter in Shared mode.

The problem of Parallels not respecting the .dwl file lock is solved by having all Parallels users change their virtual network adapter type to Bridged, then connect via Windows networking.  I did not check AFP on the Macs, because all of the Macs in our office now use SMB.  This will, of course, require that the Parallels user have the ability to authenticate via Windows networking (they will need a valid account name and password on the Windows or Mac server).

In a scenario between an Autocad for Mac user and a Parallels user in bridged mode, the dialog box message will be "The file is invalid," but the ops-lock is at least respsected.  It would be nice if Autocad could make a more informative dialog box, but maybe they don't have a set up to be able to test the issue.

Therefore, the issue has absolutely nothing to do with the file residing on a Mac OSX Server versus a Windows Server.  In our office it is strictly related to the method a Parallels user has set up to connect to the server.