I have an email server that's part of a messaging application, and it's going to see a lot of throughput. I want to mount Exim's message queue on a RAMdisk to maximize performance; throughput speed is most important, as opposed to solidarity in case of a crash or system reboot. I've found lots of information saying that mounting the message queue on a RAMdisk will help quite a bit, but no real information on how to do this.
I'm pretty certain the message queue is in /var/spool/exim by default, and that I can use tmpfs to mount a RAMdisk. How exactly would I go about mounting a RAMdisk upon bootup, and having Exim's message queue use it?
I.e. what would the command be to mount this RAMdisk, and where would I put that command so that it executes when the machine boots (but before Exim starts up)?