Can Webreach access information on a mapped drive?



Short answer: No
To display the network diagram, Webreach needs to poll out some information from the ud folder, located on the IIS server (usually the ION Primary server, but it can be different - see "Deployment of the Web Reach Web Application on a Separate Host from the Primary Server").

In some case, it might be convenient to access the server using a mapped drive instead of the full computer access path on the network.
For example using "Y:" instead of "\\<computer_name>\ION_Ent\". The location "Y:" points directly to the IONEnterprise shared folder on the server. This could be convenient for example to setup a disaster recovery plan.

However, this function is not working. Webreach cannot access the diagram located under "Y:"

Error reads:

  • The diagram does not exist, or you do not have permission to access it

The address bar contains the mapped drive location "Y:" which causes the problem.

The fact that we cannot use mapped drives with Webreach is actually a limitation of the IIS. The Microsoft KB article 257174 ( gives a really good explanation:
"When you create or administer a Web site or virtual directory, the option to browse for the physical location where the content is stored for that site or virtual directory includes mapped drives. This may be interpreted as a way to keep the content on a network share accessible through the mapped drive; however, because the nature of drive mappings, this is not a viable option. If you prefer to keep your content on a remote computer, then create the Web site or virtual directory with a universal naming convention (UNC) path to point to the share on the remote computer."
Generally, the problem is that the mapped drives are set on a per-user basis.  The user who has mapped the drive is not the same user (IUSR_<machine>) who is trying to access that drive from Webreach. There is a workaround in the Microsoft KB articles above, but it is longer than using the actual server location ( \\< computer_name>\ION_Ent ), and this is not supported by Schneider Electric.

Last Revised: November 14, 2007
Applies To: ION Enterprise
All content © 1992-2007 Schneider Electric

Legacy KB System (APS) Data: RESL189198 V1.0, Originally authored by KBAdPM on 11/15/2007, Last Edited by KBAdPM on 11/15/2007
Related ranges: ION Enterprise V5.6, ION Enterprise V5.5