Advice on image uploading

[SixTimesEight]

I'm building a site which will allow users to upload images (CentOS/Apache/MySQL/PHP). The user will select an image to upload from their local machine then see a preview of the image and be prompted to select an area of the image for a thumbnail. Then both the full size and thumbnailed images will be saved to the server with a randomly generated 32 character filename (saved into mysql).

My testing site has all of the images being dumped into /image/uploads for full size images, and /image/uploads/thumbs for the thumbnails. After uploading quite a few test images I realized that I might have a scalability problem.

My initial thoughts on a better directory structure are this:
/image/uploads/%year%/%month%/%day%/
/image/uploads/thumbs/%year%/%month%/%day%/

Is this a solid solution or is there a better idea? Should I just continue to let them pile up in a single directory. Any advice would be appreciated.

[your_store]

I would segment by the filename..

For example, with a ten character filename 123456790.gif

/image/uploads/123/456/123456790.gif
/image/uploads/thumbs/123/456/123456790.gif

I definitely wouldn't keep throwing them in one directory though :)

[SixTimesEight]

Thanks. That seems logical enough and probably easier to manage. With a 32 character file name, how many levels deep should I take it though?

[edited by: SixTimesEight at 11:35 pm (utc) on Oct. 5, 2007]

[your_store]

It really depends on the number of files you're anticipating, but two levels should be more than enough.