Squid external overview

diskd
What is it?
Based upon external processes communicating to squid using SYSV shared memory and message queues
Each storedir has a single external diskd process handling IO

Pros
Works on any platform with SYSVSHM and SYSVMSG support
Nearing the speed of aufs

Cons
Again memory-memory copies, which at the moment can not be avoided (you need to copy to shared memory)
No read / write cluster support