/3GB switch in 2003 Exchange svr with 1-2GB of RAM.. do i need it?

[Mike_Deardurff]

Hello,

Im currently trying to troubleshoot a Veritas/VSS error and per a microsoft document they referencere removing the /3GB swith in the boot.ini. Now ive done some research and found this switch is useful for applying more mem resources to apps in situations of Exchange and SQL, etc. My server is 2k3 SP2 with Exchange, however, im only running it with about alittle over 1GB of RAM right now. The exchange evironment is small and not very needy as far as resources, however, it seems to be demanding more lately so I will probably bump it up to 1.5 or 2GB.. Either way, Im assuming i can delete this switch from the .ini file? right? Since Im not even using that much memory in my system, would the swithc even provide any use? I guess i just want to remove the switch to see if it will affect my other backup problem but dont want to jeapodize system performance if it is actually helping, which i think its not.

Thanks!

-Mike

[klich · Accepted solution]

I would recommend removing it, especially with the VM only allocated 1-2GB of RAM.

/3GB usually causes more problems than it is worth. When this switch is enabled, it starves your system kernel mode memory pools, which can cause performance issues.

Clint Huffman has a very good Windows performance blog, you'll find that this post details the issue quite nicely:

Also check out the PAL (Performance Analysis of Logs) utility - - this utility will process Perfmon log files and generate a report that details performance issue observed based upon the MS performance team best practices.

[aguacero]

If your Exchange server is running less than 3 GB, then definately remove the switch. For performance sake, you may want to increase the VM memory to 2 GB.

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[Mike_Deardurff]

Thank you. I was kinda thinking along the same lines. I will try that and see how performance goes. Do you also think it smart to allow Windows to set the page file automatically? Previously it was physical machine prior to its conversion and had a 5GB page file assigned on a separate drive. Im wondering if there is any harm in moving the windows page file back to C: and letting windows choose the correct size, or just assigning it to about 2GB or so. thoughts?

Thank you

-Mike

(i will assign points when thread is complete) :smileygrin:

[aguacero]

From my experience, I rarely allow Windows control the page file. I hardset the minimum & maximum to the same number so there is no additional overhead by Windows. Take a look at what Windows "recommends" for page file and adjust it to the nearest 100 within the minimum & maximum areas.

If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!