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HunterX3
Asked: 2013-08-27 06:52:28 +0800 CST

SQL Server Page File On 3TB San Drive

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We have a Windows Server 2008 R2 box with 288GB of RAM. The system has created a page file about about the same size. This is expected, however, when I try to move the file to a SAN drive that is mounted as a 3TB GPT disk, the tool doesn't see all the available space. Windows reports the correct free space in every location I can look, except for the Virtual Memory GUI tool. Can someone tell me why and/or how to fix it so I can put the page file on this 3TB drive? The tool reports 203,965 MB free when the drive as over 2.5TB free.

windows

1 Answers

  1. Best Answer

    Generally, there's no need for a pagefile that approaches 300GB. There are a few reasons why you might want your pagefile to be as large as your RAM on Windows:

    1. A crash (BSOD) will be able to dump the whole system RAM to a crash dump. Good luck analyzing a 300GB crash dump or sending it to Microsoft for analysis. You're better off with minidumps in this case.

    2. You have an application that's trying to commit double the system RAM, which will cause out of memory crashes. If you have 288GB RAM and this is happening, you really need to add more RAM and not rely on the pagefile. I can't imagine having 200GB+ of committed memory on the pagefile. Your storage admin will probably kill you in your sleep.

    Other than that, there's not really a benefit to having (pagefile == RAM) on a server. You're better off profiling your application, checking out how many committed bytes are typically in use, and if that is larger than your RAM, take the leftover and adding a comfortable overhead and using that value for your pagefile.

    For example, if you have 288GB RAM and you typically have 300GB of committed memory, you might want a 20GB pagefile (12GB for paging to satisfy your memory commitment requirements + 8GB for overhead).

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