NAM is a high-performance but resource-demanding solution. When deployed within any environment, it will try to consume all available memory and utilize all CPU cores as needed.
Impact of NAM Probes, report servers, and Database Servers on VMware environment
This is not a problem when NAM is deployed on a dedicated server where the spare resources are left unused. However, in a virtualized environment the demand for memory and CPU power can potentially impact other virtual machines co-hosted on the same ESX server.
Therefore, we highly recommend that you install heavy-load NAM Probes, report servers, and database servers in virtual environments on dedicated ESX servers. This will prevent excessive resource appropriation that could occur both ways (NAM consuming resources needed by other virtual machines and vice versa) and in the longer perspective allow NAM to work much more effectively.
Performance impact on monitoring capabilities
When deciding upon NAM Probes and report server placement, it is important to understand the hardware requirements of our solution and the consequences of not using the recommended setup. Probably the most important thing to note is the ability to use custom drivers for network adapters within NAM Probes. Performance tests indicate that the native driver is about 50 percent slower than the custom driver when used in a typical application monitoring configuration.
Results are similar with SSL decryption cards, which cannot be used within virtualized environments. In some cases this may be unacceptable given the fact that the OpenSSL algorithm (an alternative for using SSL cards) does not provide comparably powerful key storage encryption mechanisms.
We recommend that any virtualized NAM component reside on a dedicated ESX host so it will not impair customer production applications. An exception to this would be a virtualized NAM Probe on a production host, used in cases where a Nexus 1000V, Net Optics Phantom Tap, VMware vDS span, or similar technique cannot be used to direct packets to a remote NAM Probe.
All of the above directly or indirectly may influence the performance of NAM and in some cases prevent it from working at full capacity.
Given that fact and also the limitations that virtual environments impose on the host environment being used, we generally recommend that, when possible, you deploy NAM on the recommended hardware.