Limiting available RAM for AOS (AX32Serve.exe) on Microsoft Dynamics AX 2012

Several users reported issues with Dynamics server being unresponsive while certain processes are running. On the application server, I found the AOS process AX32Serv.exe utilising almost all available RAM, which affected the OS and user’s sessions. Since the guys who were hired to deploy and customise the system were not able to help with this, I asked on Dynamics community forum and got a response from Tommy who advised to limit the available RAM for AOS.

Infrastructure: vSphere v5
OS: Windows 2008 R2 SP1
Application: MS Dynamics AX 2012

Basically, there are several ways to do this. I used the server configuration tool to create a new configuration instance and modify it by editing its configuration file.

Creating and loading a new configuration instance requires a reboot of AOS service, so a short outage needs to be planned.

Importing a new configuration file does not cause any outage.

Steps:

Open Microsoft Dynamics AX Server Configuration Utility > Manage > Save configuration as file > and make a backup of the running config.

Manage > Create configuration > name it > select Copy configuration from: Active configuration > OK > Apply > click Yes to restart the service.

Once the new configuration is shown under “Configuration:” field > Manage > Save configuration as file.

Edit the file and at the end of it, add the configuration command – e.g. to limit the available RAM for AOS to 75% of the total available RAM on the server, add the following line:

MaxMemLoad,Text,75

Note: It's important you use the config file of the new config instance as these files have some kind of a header at the beginning (a line of text with the config instance name), so if you try to reuse the file from the original config, it will pop-up an error saying "you cannot modify the original config". You could probably change the header, but I haven't tried this. So, create a new config instance and load it, save config file, edit it, and import back to the active config instance.

More info:
Application Object Server (AOS) configuration commands [AX 2012]