What should I do if Windows IIS cannot use mapped driver?

If Windows IIS cannot use a mapped drive, the issue typically stems from permission limitations or configuration restrictions. IIS runs under a specific user account (e.g., Application Pool Identity or Network Service), which may not have access to the mapped drive. Mapped drives are user-specific and not recognized by system services like IIS.

Steps to Resolve:

1. Use UNC Path Instead of Mapped Drive
   Replace the mapped drive letter (e.g., Z:\) with the full UNC path (e.g., \\ServerName\ShareName). IIS can directly access UNC paths if the application pool identity has proper permissions.

2. Grant Permissions to the Application Pool Identity

   • Identify the application pool identity (e.g., IIS AppPool\YourAppPoolName).
   • Grant read/write permissions to this identity on the shared folder.
   • Example: Right-click the shared folder → Properties → Security → Add the identity and assign permissions.

3. Check Network Connectivity and Share Permissions
   Ensure the server hosting the share is accessible from the IIS server. Verify both share permissions (on the shared folder) and NTFS permissions (on the folder itself) allow access.

4. Avoid Using Mapped Drives in IIS
   Mapped drives are not reliable for services. Always use UNC paths for shared resources in IIS configurations.

Example Scenario:

If your website in IIS needs to read files from a network share Z:\Data, replace Z:\Data with \\FileServer\Data in your application’s configuration (e.g., file upload paths or database connections). Then, grant the application pool identity (e.g., IIS AppPool\DefaultAppPool) access to \\FileServer\Data.

For scalable file storage solutions, consider Tencent Cloud File Storage (CFS), which provides high-performance, shared file systems accessible via UNC paths, ideal for IIS and other applications.