Platform: All Platforms Applies to: COMSOL Model Manager Versions: 6.1, 6.0

Problem Description

A warning message is shown informing me of potential data loss when I try to add a local Model Manager database stored on a cloud drive.


Cloud storage software typically allows files to be placed in a local file system folder whose contents is automatically synchronized with a remote cloud drive. This enables you to both easily share such files between different computers as well as get an automatic backup of the files. It may therefore be tempting to place your local Model Manager database in such a cloud drive location. However, doing so may lead to data corruption and Model Manager will warn if such a location is seemingly used.

Depending on the particular cloud storage software, the issues that may arise include:

  • Synchronization conflicts and inconsistencies. Cloud-based backup tools typically use two-way synchronization which may lead to conflicts and inconsistencies if changes are made to the database from different computers.
  • File count limits preventing complete synchronization. Some cloud storage providers limit the number of files that are synchronized between the local file system and the remote cloud drive.
  • Bugs in the cloud storage client. A database is sensitive to even slight corruption, for example missing files or incomplete file system writes.

The solution is to move your Model Manager database to a local file system location, outside any cloud drive folder. You may still use synchronization tools to back up your database as long as the tool only synchronizes in one direction — from the local database directory to the backup location. It is also important that you either first close all COMSOL Multiphysics instances connected to the database or use a backup tool that is file system snapshot-based to not risk reading data before files are completely written to the file system.

Alternatively, consider installing a Model Manager server and accessing a database hosted there as a server database in COMSOL Multiphysics. The storage of the database is then managed centrally, and additionally it allows for collaboration between multiple users of the same Model Manager database. Installing a Model Manager server requires a network license, for example an FNL license, but COMSOL Multiphysics users with CPU and NSL licenses are allowed to connect to the Model Manager server once installed.