Hi,

We have an Exchange organization with 2 CAS and 2 Mailbox Servers. Mailbox servers have 32 GB RAM. The issue is that one database was mounted on Mailbox Server (MBX1), and there were hardly 50 users in that database but Mailbox Server was taking 75% RAM. This happens to all mailbox servers that RAM usage is  high on every mailbox server. All servers are Exchange 2013.

Can you please suggest something about this issue?

Thanks & Regards,

Anees

• Edited by AneesUrRehman 22 hours 34 minutes ago changed

High Memory Utilization by store.exe are common for Ex2010 /2013. This is the architecture change from Ex2010 / 2013. Memory will be releaesd whenever other process requires it.  You have to check if CPU usage is very high, if CPU is high then you need to verify the performance of servers in terms of rpc / disk iops etc.

Thanks Vishwanath.S,

CPU usage was not high. Memory keeps getting high every day. It seems that processes do not release memory. Is there a way to manually retrieve memory from processes?

Regards,

Anees

manual = reboot. As 'Vishwanath.S" said, Exchange is designed to release memory when other processes need it.  You can always add memory to your server, as long as your hardware supports it.

I wouldn't worry about high memory utilization on the server until it logs any error or any other processes are getting crashed. This is the normal behavior of any version of Exchange to utilize as much as memory to keep the database cache and reduce the disk IO for faster performance to end-users but it also releases whenever other processed demand the memory. Server reboot releases memory but it will reach to same memory usage in a bit and you will be back in to the same situation...

However I would keep an eye on some of the basic memory counters like below...

ounter	Description	Threshold
Memory\Available Mbytes	Shows the amount of physical memory, in megabytes (MB), immediately available for allocation to a process or for system use. It's equal to the sum of memory assigned to the standby (cached), free, and zero page lists. For a full explanation of the memory manager, refer to Microsoft Developer Network (MSDN) or "System Performance and Troubleshooting Guide" in the Windows Server 2003 Resource Kit.	Should remain above 5% of total RAM.
Memory\% Committed Bytes In Use	Shows the ratio of Memory\Committed Bytes to the Memory\Commit Limit. Committed memory is the physical memory in use for which space has been reserved in the paging file should it need to be written to disk. The commit limit is determined by the size of the paging file. If the paging file is enlarged, the commit limit increases, and the ratio is reduced. This counter displays the current percentage value only; it isn't an average.	If this value is more than 80%, it is an indication that the system is likely under stress to provide more memory.

Reference : Exchange 2013 Performance Counters -  https://technet.microsoft.com/en-us/library/dn904093(v=exchg.150).as

Also I hope you have enough memory specs as per the guidance: 

Ask the Perf Guy: Sizing Exchange 2013 Deployments - http://blogs.technet.com/b/exchange/archive/2013/05/06/ask-the-perf-guy-sizing-exchange-2013-deployments.as

If we are talking about Exchange 2013, high memory usage is not normal. The store process should not use more than 25-30% of available RAM typically. This is unlike previous versions of Exchange.

Ah, you are right Andy, how did I missed Managed  Store for Exchange 2013...

Hi,

The behavior you see on the mailbox servers for store.exe is normal. This is in order to allocate as much data in memory address space as possible, so that each user experience great performance in their Outlook clients. If another process should need the more memory, the Exchange store.exe process will released it as required. This is by design.

In addiction, the noderunner.exe is used by the new Exchange search, FAST search engine, to provide more robust indexing and searching. And if you stop the Microsoft Exchange Search Host Controller service, the processes will be stopped. When you see noderunner.exe running it is going through all your email data stores and emails spidering and indexing all emails so that when users run a search in outlook or OWA, the results are returned in super fast time.

It is recommend that when designing an Exchange 2013 solution that you reserve 15% of memoryfor this particular process.

Regards,

David