Disk IO Performance Limitations based on numbers of folders/files

Question

I have an application where users are allowed to upload images to the server. Our Web Server is a windows 2008 server and we have a site (images.mysite.com) that points to a shared drive on a unix box.

The code used to do the uploading is C# 3.5.

The system currently supports a workflow where after a threshold is met a new subfolder can be generated. The question we have is how many files and/or subfolders can you have in a single folder before there is a degredation in performance - in serving the images up through IIS 7 and reading/writing through code?

Answer 1

We had a site which hit 350,000 image files in a single directory. The site operates just fine serving those images. The problem comes in when you try to view that directory in Explorer. Explorer is interested in sharing with you more than the file name; it wants to show you an icon, and other properties such as image size which it has to obtain by reading the file itself.

The subfolders are more a convenience for the administrative individuals that have to manage those resources.

You may want to set a file count threshold parameter starting at about 10K per folder and tune it up based on how well that folder can be navigated in Explorer.