I got error "OutOfMemoryException: Exception of type System.OutOfMemoryException was thrown"

SUMMARY

During the upload process, ASP.NET loads the whole file in memory before the user can save the file to the disk. Therefore, the process may recycle because of the memoryLimit attribute of the processModel tag in the Machine.config file. The memoryLimit attribute specifies the percentage of physical memory that the ASP.NET worker process can exhaust before the process is automatically recycled. Recycling prevents memory leaks from causing ASP.NET to crash or to stop responding.

Additionally, other factors play a role in the maximum file size that can be uploaded. These factors include available memory, available hard disk space, processor speed, and current network traffic. With regular traffic of files being uploaded, Microsoft recommends that you use a maximum file size in the range of 10 to 20 megabytes (MB). If you rarely upload files, the maximum file size may be 100 MB.

You may notice the following error messages if you encounter file size limits during the file upload process then using ASP.NET built-in upload class:

• The page cannot be displayed.
• Server Application is Unavailable.
  In the event log, the error message will be similar to the following: aspnet_wp.exe (PID:PIDNumber) was recycled because memory consumption exceeded the SizeLimit MB (Percentage percent of available RAM).
• Exception of type System.OutOfMemoryException was thrown.

SOLUTION

PowUpload ASP.NET control handles and stores the contents of the POST request to a file on the server hard disk rather than loading it into memory as the built-in ASP.NET upload support does so you willn't have problems with memory use while uploading large files.

REFERENCES

Microsoft KB Article:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;295626