This Microsoft article - How to determine the appropriate page file size for 64-bit versions of Windows Server 2008 and or Windows 2008 R2 provides guidance for calculating the page file size for 64 bit Windows 2008 and Windows 2008R2. This no doubt works fine for general purpose servers. I'm wondering what the guidance is for SQL Server 2008R2 running on Windows 2008/R2 64 bit?
I'm presuming we want as little in memory data to be hitting the page file otherwise SQL could be hitting the disk twice for data. Does SQL Server even allow data in memory to hit the page file? I've hunted through SQL Server 2008 R2 Books Online for guidance but haven't yet found any mention of page file use.
Here's a potential usage scenario: Given a physical server with 64GB of RAM, is a pagefile necessary for the entire 64GB of RAM? Should we gear it up for 96GB of pagefile? That does seem a bit excessive for a single file. I know conventional wisdom has been that Windows couples pagefile to memory in an attempt to make swapping out apps easier on RAM, but is that true? Will a less than 64GB pagefile hinder performance here?