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.
Note You can upload files that are larger than 100 MB in ASP.NET. However, Microsoft recommends that you follow the maximum file upload sizes that are mentioned in this article. To determine more precise file sizes, perform stress testing on computers that are similar to the ones that will be used in production.
You may notice the following error messages if you encounter file size limits during the file upload process:
- 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.
You may also find that uploads occur very slowly.
If you watch the Aspnet_wp.exe(IIS 5) or w3w.exe
(IIS 6/7) process in Windows Task Manager, you will
notice that the memory delta changes by 64 KB every
1 to 2 seconds. Depending on the size of the file,
this delay may cause the ASP.NET worker process to
recycle because of a responseDeadlock error.
APPLIES TO
- Microsoft ASP.NET 1.1
- Microsoft ASP.NET 1.0