I am a paranoid person by nature and I am looking for a justification for my setup at one of my clients offices. We are running an exchange server with 20gb of ram and the client wanted it virtualized. We were unable to do so because the hardware did not support Esxi and the maximum memory limit on the vmware server is 8 gb per machine. we have 20 gb of ram 16 users and LCR running. I want to justify to my client that 16 gb is a minimum he should consider because of a critical nature of his setup. the recommended requirements are 8+ mailboxes which would make it 12gb. would LCR increase it to 16 gb? also is there a fact about excessive caching in exchange below 16 gb of ram? Please give me your thoughts and comments

@ present what you is more than sufficient Configurations. See below table to understand about the same Mailbox server memory recommendations User type Mailbox server memory recommendation Light 2 GB plus 2MB per mailbox Average 2 GB plus 3.5MB per mailbox Heavy 2 GB plus 5MB per mailbox Very heavy 2 GB plus 5 MB per mailbox Extra heavy 2 GB plus 5 MB per mailbox Minimum memory required based on number of storage groups Storage group count Exchange 2007 minimum required physical memory Exchange 2007 Service Pack 1 minimum required physical memory 1-4 2GB 2GB 5-8 4GB 4GB 9-12 6GB 5GB 13-16 8GB 6GB 17-20 10GB 7GB 21-24 12GB 8GB 25-28 14GB 9GB 29-32 16GB 10GB 33-36 18GB 11GB 37-40 20GB 12GB 41-44 22GB 13GB 45-48 24GB 14GB 49-50 26GB 15GB http://technet.microsoft.com/en-us/library/bb738124.aspx Also this one http://www.msexchange.org/articles-tutorials/exchange-server-2007/planning-architecture/exchange-2007-sizing-cheat-sheet.html Vinod |CCNA|MCSE 2003 +Messaging|MCTS|ITIL V3|

Vinod is quite right on MS' recommendations. And while we're used to that those recommendations are far to low, this is no longer necessarily true. We are running about 1000 users on 16 GB dual quad Xeon 2.5 CCR. The databases are about 1.2 tera all in all. And there is more to come (however then we will ad more RAM). If I remember well LCR adds about 20-30 % of processing and 1 GB of memory (David Shackelford in his superb Train Signal course). Don' forget you have to have anti-virus which at least adds up to 1 GB. Then this will not be a pure mailbox server, but in addition run Hub and CAS. MS' recommendations should still be considered as a bit too low. A common workstation / portable should have 4 GB these days. My workstation has 8 GB ... 10-12 GB could easily be justified for a server. It might be more difficult to justify an Exchange Server for 16 users in a branch office. MS has 120 000 or so users with only three data centers. On the other hand, if you virtualize, and add more sever roles ... ESXi is not supported, what about Hyper-V on Windows 2008 R2. (I think there is a free limited edition). It's a mind-blowing product. Just my two cents before I go to sleep. jas

The Storage calculator calculates the storage need as well as the RAM and other considerations. Here you can input information aboutLCR and other considerations, and the adjustments are reflected in the output:http://msexchangeteam.com/archive/2007/01/15/432207.aspxAdditionally, you can use the System Center Capacity Planner program, but I prefer the above spreadsheet.http://www.microsoft.com/systemcenter/en/us/capacity-planner.aspx

Good Info To calculate