We help IT Professionals succeed at work.

page file size and location

capvac
capvac asked
on
14,211 Views
Last Modified: 2013-12-14
I am running ntserver 4 with the following disk structure:
1st physical disk; 2 gig partition for O/S, extended partition on this disk is logical drive of 38 gig for apps and data.
2nd physical disk; logical drive of 80 gigs (nothing on here, just used for backups and storage)
I went from 512 Megs of RAM to 1000. My page file is now to small (512 to 562 max). Microsoft recommends putting your page file to a separate disk  (or at least a different partition than your system partition) and leaving the original on the system partition for memory dumps. As it stands now, I have a notification in event viewer that my crash dump is disabled due to memory size.
If I understand the recommendations, I should have a page file equal to one and a half times my physical memory. Obviously, I can’t do that on the system partition. So, I’m trying to determine the best way to create my page files; should I increase the one on my system partition? Put one the data partition? Put one on the second disk? How do I determine the initial size and the maximum size for each?
Thanks


Comment
Watch Question

CERTIFIED EXPERT
Top Expert 2007

Commented:
>>
By default, Windows places the pagefile on the boot partition where the operating system is installed. To determine the size of the pagefile multiply the amount of physical RAM by 1.5 to a maximum of 4095MB. However, placing the pagefile on the boot partition does not optimize performance because Windows has to perform disk I/O on both the system directory and the pagefile. Therefore, it is recommended that you place the pagefile on a different partition and different physical hard disk drive so that Windows can handle multiple I/O requests more quickly.

However, completely removing the pagefile from the boot partition does not allow Windows to create a crash dump file (Memory.dmp) should a kernel mode STOP error occur. Not having this crash dump file could lead to extended server downtime should the STOP require a debug to be performed.

The optimal solution is to create one pagefile on the boot partition using the default settings and create one pagefile on another less frequently used partition. The best option is to create the second pagefile so that it is on its own partition, with no data or operating system-specific files.

Windows will use the pagefile on the less frequently used partition over the pagefile on the heavily used boot partition. Windows uses an internal algorithm to determine which page file to use for virtual memory management. In the above scenario, the following goals of the page file would be served:


The system will be properly configured to capture a Memory.dmp file should the computer experience a kernel mode STOP error.
The page file on the less frequently used partition will be used the majority of the time because it is not on a busy partition.
<<ref:http://support.microsoft.com/?kbid=197379
CERTIFIED EXPERT
Top Expert 2007

Commented:
>>The only downside to a too large page file size is that you are consuming some of your disk space unneccessarily. Given the size of modern disks, this seems to be a trivial issue. Under Windows NT, the page file occupies a contiguous block of space in the partition. If possible split the page file between hard disks. Don't split the page file across partitions created on the same hard drive since that will decrease performance.

The downsides of a too small pagesize are much more serious. At a minimum, your system will experience disk thrashing where your pagefile files to maximum and NT is constantly swapping out segments of RAM to disk virtual memory. This can really impact performance. It can also result in a corrupted pagefile. Additionally, the pagesize should be at least the size of RAM+1MB in order to support core dumps. In any case, you have swapped out the fasted component in your server for the slowest. << 
ref: http://is-it-true.org/nt/atips/atips178.shtml
Also: http://www.forensics-intl.com/def7.html

Author

Commented:
Ok, so set me straight here. I cant really put the proper size page file (for crash dumps) on the system partition because, the partition is only 2 gigs with 1.02 gigs free. I have 1 gig of physical memory on the board.
Should I leave that pagefile as is, or increase the size? If its not as big as the amount of RAM will it be effective in the event of a crashdump?
But, I can put a second page file on the second disk for virtual memory and I would configure it to be 1100 meg min? should I set the max to 1.5 times the ram? in this case 1.5 gigs?
thanks
CERTIFIED EXPERT
Top Expert 2007
Commented:
Unlock this solution and get a sample of our free trial.
(No credit card required)
UNLOCK SOLUTION
Unlock the solution to this question.
Thanks for using Experts Exchange.

Please provide your email to receive a sample view!

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.