Just wondering, have you ever made anything useful with a RAM disk in production? I wonder if the performance benefit they afford possibly outweighs their temporary nature in a specific circumstance.
I've only ever used one once, and it wasn't for performance. It was when I needed some writable disk space on a server showing hard drive errors – it gave just enough space for me to install the 3ware RAID utility to identify the dodgy disk.
How have you used a RAM disk in production?