Dear all, I have faced some issues with memory configuration for exchange server 2003 especially when using PAE and 3GB switches together on some of the machines. The machines would not start normally and woudl go offline until I remove the parameter? Is this a known issue? if it is why is it so? and if we have more than 4 GB of RAM on the server, how to properly utilize that memory? Thanks in advance.

Exchange Server 2003 cannot address more than 4 GB of RAM nomatter what you trie to do. Your options from here is to scale out by adding additional Exchange Servers ... or of course transition to x64 architecture (Exchange 2007/2010).Jesper Bernle | Blog: http://xchangeserver.wordpress.com

Its not a known issue, but keep in mind that if your server is already under stress adding the PAE switch can actually make it worse. Using the PAE halfs your number of availabe system page table entries which can cause system issues, drivers, HW etc. James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Some more info on Free PTEs - The number of free page table entries is low, which can cause system instabilityJesper Bernle | Blog: http://xchangeserver.wordpress.com

Hi, As above mentioned, Exchange Server cannot use more than 4 GB of physical memory, and there is no benefit to installing more than 4 GB of RAM on a computer that is dedicated to running Exchange Server. For more information, please refer to the following article: http://blogs.technet.com/b/exchange/archive/2005/07/05/407330.aspx Thanks. NovakPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

You can also use the /burnmemory parameter in boot.ini to reduce the memory seen to 4GB - http://technet.microsoft.com/en-us/library/aa997419(EXCHG.80).aspx - unless you are running other things than Exchange on the server. That page also links to a hotfix ( http://support.microsoft.com/?kbid=834628) that can help with some Exchange issues if you for some reason need to keep more than 4GB on the server (i.e. the server runs other things and isn't dedicated to Exchange.) Yes, the kb article refers mostly to SQL server but it's really related to Windows memory management.