IIS 7.5 – uploadReadAheadSize

IIS 7.5 – uploadReadAheadSize

A developer recently reported a problem that when a customer attempted to upload an attachment, they would sometime receive the error:

The page was not displayed because the request entity is too large.

In our case it did not include an error number, but it will sometimes include the error number:


The fix for us is listed below:

How to set the uploadReadAheadSize in IIS 7.5

  1. Launch “Internet Information Services (IIS) Manager”
  2. Expand the Server field
  3. Expand Sites
  4. Select the site you want to make the modification for.
  5. In the Features section, double click “Configuration Editor”
  6. Under “Section” select: system.webServer>serverRuntime
  7. Modify the “uploadReadAheadSize” section
  8. Click Apply
– Note that the value is in BYTES
Source: http://tips4sysadmins.blogspot.com/2012/12/iis-75-uploadreadaheadsize.html