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Uploading Large Files

Sometimes users need to upload files larger than 4GB, but the IIS would prevent them to do so. You can allow users to upload files with a combined size larger than 4GB, but this requires some modifications in your application configuration files.

Setting the Configuration File of the Application

In order to upload files larger than GB, you need to change the following attributes of the <httpRuntime> tag in the <system.web> section of the Web.config file.

  • maxRequestLength

The maxRequestLength attribute specifies the limit for the input stream buffering threshold, in KB (kilobytes). You can use this limit to prevent denial of service attacks that are caused, for example, by users posting large files to the server. The default value is 4096 (4 MB).To enable large file uploads you need to change the value of this attribute to the largest allowed combined file size for your application. If someone selects and uploads files with a total size larger than maxRequestLength, this will result in a "Page not found" error. RadCloudUpload does not provide a way to handle this error.

The MaxFileSize property of the RadCloudUpload control specifies the maximum size of each of the uploaded files in bytes.

  • executionTimeout

The executionTimeout attribute specifies the maximum number of seconds a request is allowed to be executed before being automatically shut down by ASP.NET – the default time is 110 seconds. If a request takes longer to execute, an exception will be thrown.To enable large file uploads, which can take large periods of time, you should increase the value of this property.You can find more information about the httpRuntime configuration in the following MSDN article:

How to Modify the Configuration File of the Application

To make modifications to your application for large file uploads, you need to:

  1. Open the Solution Explorer, navigate to the application Web.config file and open it.

  2. Under the <configuration> element, locate the <system.web> element. Add it if it does not exist.

  3. Under the <system.web> element, locate the <httpRuntime> element. Add it if it does not exist.

  4. In the <httpRuntime> element, locate the maxRequestLength and executionTimeout attributes. If they do not exist, add them.

Modify the configuration file to allow uploads of files of up to 100MB and upload periods of up to 1 hour:


      <httpRuntime maxRequestLength="102400" executionTimeout= "3600" />

The configuration file sections and attributes are case sensitive . This means that the sections and attributes below will be incorrect if written using a case other than shown.

Settings for IIS7

  1. Add these lines in the Web.config file:



  2. Open the file C:\Windows\System32\inetsrv\config\applicationHost.config and find the line: <section name="requestFiltering" overrideModeDefault="Deny" />

  3. Change the overrideModeDefault property from "Deny" to Allow. So now the line should look like: <section name="requestFiltering" overrideModeDefault="Allow" />

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