Unix VM
	• Physical Memory – Core map (pinned) – page frame info – Kernel (pinned) – rest of kernel – Frames – remainder of memory • Page replacement – Page daemon • runs periodically to free up page frames • Global replacement – multiple parameters • Current BSD system uses 2-handed clock – Swapper – helps page daemon • Look for processes idle 20 sec. or more and swap out longest idle • Next, swap out one of 4 largest – one in memory the longest • Check for processes to swap in