Very bad network access bug
We have had a bad problem with opened files not being properly locked on a network (they can be acessed by two users simultaneously). This causes drawing corruption and loss of work. Partly because of this problem, we upgraded to a Win XP environment in our office. To my disappointment, the problem persisted.I have recently found this to be related to a combination of the Autosave function and changes to the drawing database (e.g. drawing a line)Test case 1: Savetime = 1 (minute), open a drawing, draw a line. Wait for autosave to kick in (toggle F2 if it doesn't after a while). Open drawing from another computer. Most likely you will get no message telling you the file is already in use.Test case 2: Savetime = 1 (minute), open a drawing, do nothing. Wait for autosave to kick in. Open drawing from another computer. You should get a message telling you the file is already in use.Test case 3: Savetime = 1 (minute), open a drawing, draw a line. Wait for autosave to kick in . Qsave drawing. Open drawing from another computer. You should get a message telling you the file is already in use. In other words, qsave puts back in place the lock lifted by autosave.
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We do not experience any of these file problems on our network, using Novell netware on our network server and Win-XP on our CAD computers. It's simple to set Netware file/user acess rights to automatically make the files sharable or non shareable read only or read/write, to protect against multiple user write access
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Thanks, Interesting to hear this is not a problem when using Novell. We use Microsoft Network. I'm still blaming Intellicad because it only happens with Intellicad, never with Autocad or any other program on our network. I hope Bricscad will be able to duplicate the problem and fix it, because it really is not an acceptable situation.
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We are having the same problem on our Microsoft network. It seems to be with the save and autosave feature - loading the file seems to work just fine. It also seems to be affected by the number of xrefs.
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It's not suprising that MS network software is experiencing these problems and Netware software does not have this problem. MS uses very strange proprietarynetwork file access algorithems...while Netware follows an international ISO standard.
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Fact remains that this does not happen with Autocad on our MS network. There must be something Bricscad can do about it.
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The other fact is that this did not occur with version 2.xx of Intellicad - something has been changed in version 3.xx. Maybe it has something to do with the file locking bug.
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The problem may originate in the way XREFs are handled in newer version, for Example:If simultaneous mulitple CAD files or CAD operations XREF the same drawing file and attempt to make changes(by writing to the same shared XREF file ) this will adversly affect the XREF file(such as an auto save action) . A conflict will occur, as multilpe user simutaneously attempt to "write" their changes to the same common XREF file!! The network operating software may attempt to prevent these simultaeous "write" operations to the same file. I believe there is also a "timoout" duration value that network software will apply before the file is automatically released for another "write" operation?This condition would be true for any common file that may be refereced simultaneously through CAD by multiple users at the same time.
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Unfortunately, the "test"performed on top of this page is on an empty drawing - xrefs are not involved. Besides that, it is allowed writing to an xref'ed file, even if it has been referenced to an open drawing. This does not create any problems.
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