Technical data

Solution Architectural Overview

VMware Horizon View 5.3 and VMware vSphere for up to 2,000 Virtual

Desktops Enabled by Brocade Network Fabrics, EMC VNX, and EMC Next-

Generation Backup

the server is being actively used, vSphere might resort to swapping portions

of a virtual machine's memory.

Non-Uniform Memory Access (NUMA)

vSphere uses a NUMA load-balancer to assign a home node to a virtual

machine. Memory access is local and provides the best performance

possible because memory for the virtual machine is allocated from the

home node. Applications that do not directly support NUMA benefit from

this feature.

Transparent page sharing

Virtual machines running similar operating systems and applications

typically have identical sets of memory content. Page sharing allows the

hypervisor to reclaim the redundant copies and keep only one copy,

which frees up the total host memory consumption. If most of your

application virtual machines run the same operating system and

application binaries, the total memory usage can be reduced to increase

consolidation ratios.

Memory ballooning

By using a balloon driver loaded in the guest operating system, the

hypervisor can reclaim host physical memory if memory resources are

under contention with little to no impact on the application’s

performance.

This section provides guidelines for allocating memory to virtual machines,

which take into account vSphere memory overhead and the virtual

machine memory settings.

vSphere memory overhead

There is some associated overhead for the virtualization of memory

resources. The memory space overhead has two components.

 The system overhead for the VMkernel

 Additional overhead for each virtual machine

The amount of additional overhead memory for the VMkernel is fixed,

whereas the amount of additional memory for each virtual machine

depends on the number of virtual CPUs and the configured memory for

the guest operating system.

Allocating memory to virtual machines

The proper sizing of memory for a virtual machine in VSPEX architectures is

based on many factors. Because of the number of application services

and use cases available, determining a suitable configuration for an

environment requires creating a baseline configuration, testing, and

making adjustments, as discussed in this paper. In this solution, each virtual

machine is assigned two GB of memory in fixed mode, as listed in Table 6.

Memory

configuration

guidelines