Hello All, We are just about to build a Windows 2008 x64 Enterprise machine with 64GB of memory. No where can we find any information on how to properly set the pagefile for the system. We plan on using this system to strictlyrun virtual instances and want to get the best performance out of the machine. Do we use the old standard of 1.5x the memory to set the pagefile limits? If that is the case, we're looking at nearly 100GB of hard drive space just for the pagefile. Is there a limit that we should be aware of?? Please help! Thanks, Phil Rudich Benelogic Sr. Systems Engineer

Please take a look at Microsoft KnowledgeBase article 889654: How to determine the appropriate page file size for 64-bit versions of Windows It's the best resource from Microsoft on configuring pagefile settings on x64 versions of Windows, including Windows XP x64, Windows Server 2003 x64 and (although not mentioned in the article) Widows Vista x64 and Windows Server 2008 x64.

Sander, I've taken a look at that page... thanks! Would you know if these calculations aregoing to hold true for W2008 as well? Phil

Yes, the same calculations will apply to 2008. One thing that is not listed there that could become a consideration. With large memory configurations, Microsoft changed the way memory dumps are taken. You have the option for mini-kernel, kernel, and full memory dumps. Obviously, each type takes more and more physical disk space. And, dumps are written to the page file when they occur and then are transferred to a dump file upon the subsequent reboot. For most situations, the mini-kernel is all that would be needed for troubleshooting. However, as problems get more severe, it might require a full kernel dump. I just had a company that had to go all the way to full memory dump recently because the problem they were trying to track down was actually in user code, so they had to force a dump of their entire 32GB system. So, they ended up with the need for a 32GB page file. This was on a mission critical server. During the debugging process, they actually moved from mini, to kernel, to full. Each of these took a system reboot, meaning a break in their operations. As a result of that, they decided that for their critical application hosts, they would run with the full memory dump capability. Other servers would have smaller page files. Basically what I am saying is that there are a couple other considerations for page file size that you should consider. There is no hard and fast rule. Each company needs to make its own judgment call on something like this. tgc

Tim, Thanks for the additional info. Definitely helpful!! One last question for you all.... does anyone know if there is a limit to the pagefile size on 2008 EnterpriseEdition? I thought I read somewhere that the limit may be 128GB, but wanted to verify. Thanks again! Phil

Hello, The limitation of paging file size in Windows 64 bit OS (Starting with Windows Server XP) is 512TB. The limitation of paged pool size is 128GB. You could refer to the following articles: Top 10 benefits of Windows XP Professional x64 Edition http://www.microsoft.com/windowsxp/64bit/facts/top10.mspx Memory Limits for Windows Releases http://msdn2.microsoft.com/en-us/library/aa366778(VS.85).aspx Based on my research, this limitation also apply to Windows Server 2008 64-bit Enterprise Edition. I hope this helps. Regards, Neo Zhu