Thursday, October 23, 2014

Ever needed more than 4GB pagefile on a 32 bit machine? Split pagefile among 2 HDD.

To create multiple paging files http://support.microsoft.com/kb/237740
Try the below its not mentioned in the KB article but still its worth trying it...
  1. On the drive or volume you want to hold the paging files, create folders for the number of paging files you want to create on the volume. For example, C:\Pagefile1, D:\Pagefile2, and E:\Pagefile3.
  2. Click Start, Click Run, type regedit in the Open box, and then click OK.
  3. In the left pane, locate and click the following registry subkey:
    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\SessionManager\MemoryManagement
  4. Find the Pagingfiles value, and then double-click it to open it.
  5. Remove any existing values, and add the following values:
    c:\pagefile1\pagefile.sys 3000 4000
    D:\pagefile2\pagefile.sys 3000 4000
    E:\pagefile3\Pagefile.sys 3000 4000
  6. Click OK, and then quit Registry Editor.
  7. Restart the computer to cause the changes to take effect.
  8. Access the virtual memory settings to check the properties of the paging file. To do this, follow these steps.
From the article, split is actually helpful if your 2 disks have the same speed:
If you have multiple hard disks, splitting up the paging file is a good idea, as it will speed up the access time. If you have two hard disks, and you split the paging file, both hard disks can be accessing information simultaneously, greatly increasing the throughput. However, if you have two hard disks, and one hard disk is faster than the other, it may be more effective to store the paging file on only the faster hard disk. Some experimentation may be necessary to arrive at the best configuration for your system. 
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With the default pagefile set at - either 2GB or 1.5 x RAM for machines with RAM under 2GB
or....for machines over 2GB the page file will be set for 2GB.

Now more and more in large systems I'm seeing the need to increase this pagefile to over 2GB.

Problem - 32-bit Windows 2000/2003 can only address 4GB (as RAM) for a Pagefile.

In this particular case I have 10 biztalk host instances running on a heavily loaded machine.
The machine is 32bit (with the prospect of going 64bit in the medium future) and we need to prove the solution to the business.
(i.e volume, load, uptime etc.)

While looking at trying to expand the pagefile (I'm assuming it's not all being used, but during 'busy' times, I'd like to have a bit extra if needed)
I came across the limitation of 4GB - makes sense when you think about it. A memory mapped file, living on the disk.

Here's some handy registry settings for giving you more!!!!