User`s guide

20 Dialogic

Host Media Processing Software Release 4.1LIN Release Guide

Features

CPU Affinity Settings

To run real-time software on VMware

ESXi, use CPU affinity. This is the recommended

method for real-time voice since each virtual processor can get CPU resources directly

from one or more of the available host CPUs, reducing the likelihood that virtual

processors are rescheduled to give CPU time to another virtual machine.

Each virtual machine is more isolated, which helps real-time software run as though it

were in a physical server environment. Due to HMP software’s intensive use of the

operating system kernel resources, it is also highly recommended to set aside one

physical (host) CPU to the VMware

ESXi 4.0 hypervisor. This host CPU should not be

part of the affinity setting of any of the virtual machines.

For example, on a dual-processor, four-core host system without hyper-threading system,

there will be eight physical CPUs available to VMware

ESXi. In this scenario, two virtual

machines are configured with two virtual processors each. The system administrator

could set the first virtual machine CPU affinity to physical CPUs 0 through 3 (total 4), and

the second virtual machine CPU with affinity to physical CPUs 4 through 6 (total 3); this

leaves physical CPU 7 unassigned and available to the VMware

ESXi hypervisor.

Virtual machine configuration is accomplished using the vSphere vCenter or via the

VMware CLI. Refer to the vSphere Basic System Administration or equivalent guide at

http://www.vmware.com/pdf/vsphere4/r40_u1/vsp_40_u1_admin_guide.pdf for vSphere

vCenter information. For VMware CLI instructions, refer to

http://www.vmware.com/pdf/vsphere4/r40_u1/vsp_40_u1_vcli.pdf.

Notes:1. Be careful not to cross physical processor boundaries when assigning CPU affinity to

virtual machines, so that all host CPUs assigned to a virtual machine belong to the

same host physical processor.

2. On NUMA host servers, it is recommended to keep all physical CPUs affine to a virtual

machine residing in the same NUMA node in order to avoid a performance penalty

when accessing non-local memory.

Timing Configuration

For optimal virtual machine timing and HMP operation in a virtualized environment, it is

recommended that VMware Tools are installed in each virtual machine.

• Install VMware Tools in each virtual machine. Refer to the VMware ESXi Setup Guide

for the installation procedure.

• Use the vShpere vCenter utility (or VMware CLI) to access the host system Time

Configuration. Provide the address of an appropriate NTP Server in the Date and

Time Options, and restart the NTP service to apply the changes.

Note: VMware Tools includes an optional clock synchronization feature “Time Synchronization

between the virtual machine and the ESX Server” that can be enabled in the virtual

machines, and could conflict with the native synchronization software. Be aware that

having both enabled could affect the virtual machine’s operating system’s ability to correct

long-term wall-clock drift, hence affect HMP audio quality.