Chapter 5: Resource Allocation Guidelines

This section gives general guidelines for resource allocation for cOS Stream virtual machines for both VMware and KVM. Hypervisor specific guidelines can be found in the setup sections for VMware and KVM.

Minimum Memory and Disk Requirements

All hypervisor image files supplied by Clavister have a predefined RAM memory allocation of 1024 Mbytes. This is the minimum amount of memory required for cOS Stream to run and it should never be reduced. This default allocation may need to be increased depending on the license purchased and the number of connections/tunnels that will be open simultaneously. There is no higher memory limit.

If the allocated memory is insufficient during operation, cOS Stream will output console messages indicating this while trying to reduce the number of open connections/tunnels. Eventually, the system will enter safe mode where only management access is possible.

The minimum disk space allocated should be 1 GByte.

Overview of Memory and CPU Core Allocation

By default, cOS Stream will automatically distribute the allocated memory for the control and data planes in a virtual instance. To do this, it uses an algorithm that assigns the majority of the memory to the data plane since this is where the memory is most likely needed to handle flows and other state information that will grow with the amount of throughput. However, in some situations it may be required to change the memory distribution. This can be done by changing the ControlPlaneMemory system setting to the amount of megabytes that should be assigned to the control plane. The remaining memory will be assigned to the data plane. The system must be restarted for the change to take effect.

By default, cOS Stream will also automatically distribute the allocated CPU core resources for the control and data planes by using an algorithm that assigns the majority of CPU cores to the data plane since, in most cases, this plane is handling the majority of traffic. However, in some situations, it may be required to change the CPU core allocation and allocate more cores to the control plane. This can be done by configuring the ControlPlaneCPUCores system setting to be the number of cores to allocate to the control plane. The remaining cores will be assigned to the data plane. The system must be restarted for the changed setting to take effect.

Allocating Sockets, Cores and Threads to a Virtual Machine

The following guidelines should be noted when allocating CPU sockets, cores and threads to the virtual machine running cOS Stream: