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Why Does Exchange Allocate So Much Memory?

I have Exchange 2007 running on Server 2003 R2, 64 Bit.  The machine has Dual processors, and 18GB of memory, and a RAID-5 array.  The datastore is about 20GB in size.  Continuous local replication is enabled to the local disk.  I support about 100 mailboxes, but only about 8 concurent users.  The users have access to multiple mailboxes, many of which are shared, including about 5,000 shared contacts.  The 8 users are using Outlook 2010, running in non-cached mode.  I also have a half-dozen applications sending internal email, and use Symantec Endpoint protection to scan for viruses and as my secondary spam block.  (My primary spam filter is off-site).  An additional 20 users login about once per day to pick up a few emails.

The Server also serves as my backup DC, and as file storage.  The files are relatively small, so accessing them is not a big demand on the system.

The Exchange process store.exe uses (at times) tremendous amounts of memory (12GB to 13GB).  It will then, for no apparent reason, go down to 4GB and stay there for a while.  Then up, then down.

My users complain that there are sometimes delays in accessing their files (including application not responding delays).  These are 40K read-only files, so it can't be a big demand on the system.  (The files are accessed through DFS, but all copies are on the local subnet and this sever is the primary source).  I want to make sure that Exchange is no using up so much memory that it is pushing back file access.

Is Exchange using too much memory?  Any suggestions on how to make sure my users will not have delays in accessing their files?

Thank you,
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Top Expert 2012

Off hand, sounds as if you may have an Antivirus scanning the exchange Store

If this is the case you will want to disable it asw you will see performance issues when the store is scanned as well as this cvould lead to future corruption
Harold KrongelbPresident/Engineering Supervisor


I spoke to Symantec support about that possibility.  We went over the settings, and there are no extra scans running.
IT Manager
Distinguished Expert 2019
It is normal for Exchange 2007 to consume as much as the memory you have installed in order to maximise the database cache for faster access to Exchange server. For details, please read the link below:-


In short, the best practice is to run Exchange 2007 on a dedicated server with no other roles to be deployed on the same server.
I agree with  jackieman, MS Exchange and SQl are memory hungry applications and will consume as much memory as you have installed. This is done because accessing information for memory is much faster tha from disk..

In regards to your Exchanger servers performance I have the following questions.

1) Are your Exchange log files and Exchange DB's on the same drive or seperate?
2) Is the OS on install on a seperate drive from Exchange?
3) What is the size and location of your page file?
4) Have you used perfmon to monitor the servers: disk and memory stats?
Harold KrongelbPresident/Engineering Supervisor


To answer the questions:

1.  The OS, pagefile, Exchange store, and Exchange log files all reside on a RAID 5 array consisting of 5 physical disks (one is a spare) and divided into 2 logical volumes.  Effectively, that makes it one disk

2.  The pagefile is about 18GB, the size recommended by the system.

I agree Exchange should, ideally, reside alone.  99%+ of the user files are never changed and almost never accessed (they are archives that need to be readily accessible).  The less than 1% of the files occasionally is slow.  But investing in another server just because the file access is sometimes slow seems a little unjustified.

As far as perfmon, I have been unable to capture the moment that the system bogs down.

There are a few performance settings (give services equal CPU versus workstation-type scheduling, memory allocation to file shares versus programs, and the file cache size that I thought might be tweaked to help.  I have setup maximize file sharing and file cache, but Exchange still takes all possible memory.  I am not sure what the optimal setting for services versus workstation.)

Thank you,
I found a smilar discussion on Experts-Exchange. Please have a look.


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