When you use Revit Server for worksharing, each model is assigned a globally unique identifier, or GUID.
<?xml version="1.0"?> <CentralModel version="2.0"> <ModelIdentity>ad0b4790-65a4-4865-a23f-f5bd6c1ebeb9</ModelIdentity> <DataFormatVersion>HaveProjectInformationStream</DataFormatVersion> <PermissionsFormatVersion>AddReadableElementInfoInRequest</PermissionsFormatVersion> </CentralModel>
' 9:< Time: 2/2/2012 09:56:32:023 Beginning to download: a26f5002-281b-474d-be4e-10888a23778f\global.7980.dat|ServiceModelSessionToken(User Name > user1 : Model Identity > ModelIdentity(GUIDa26f5002-281b-474d-be4e-10888a23778f) : Client's machine name > WL-V1 : Operation GUID > 3defccd9-8148-4fcf-bb8d-e010596bb68f)
The GUID is not exposed to the end-user of Revit (by design.)
It is used to name model cache folders on the accelerator. In Revit Server 2011 and 2012, cache folders on the local server were stored in a directory structure paralleling and identical to the directory structure in use on the central server. But in Revit Server 2013, all cached models are stored in a flat directory structure by unique model GUID.
Revit Server is responsible for GUID creation and management. Failure to observe this may result in models sharing the same GUID, which could lead to data loss or corruption.
First, this condition will never occur so long as models are managed exclusively using Revit Server Administrator.
If multiple models share the same GUID, then some users' working copies may associate with one model while others associate with another. If this occurs, users may report that they do not see the changes committed by other users whom they believe are collaborating on the same model. In this scenario, the extra models (sharing the GUID) should be deleted from the system and all users should cut new locals from the one remaining copy.
Furthermore, since this can only occur if models have been managed outside of Revit Server Administrator, the CAD staff should be reminded of proper model management procedure.