Virtual CPUs allocated to a Virtual Machine (VM) is not a guarentee of resources. Understand resource contention on the ESXi host.
- [Voiceover] In this video, I'll explain how CPU resources…are allocated to virtual machines.…When you create a virtual machine, you'll allocate a certain…number of virtual CPUs to it.…The amount of CPU resources required varies from…one virtual machine to another.…Bear in mind that we are creating virtual resources…that are allocated to the VM.…So think of it this way, if we configure a virtual machine…with two virtual CPUs, we're saying that this…virtual machine can consume resources…onto physical processor cores.…
The applications and operating system that are running…on the VM will determine the required CPU resources.…When you allocate CPU to a virtual machine,…you're not guaranteeing any physical resources.…CPU instructions are scheduled on a physical process or…as needed.…That means that the virtual machine will only consume…the CPU resources that it truly requires.…So, how many CPUs should we actually give to our…virtual machines?…The answer is simple.…Give them as much CPU as they need to function properly,…
VMware Certified Instructor Rick Crisci provides an overview of vSphere resource controls—shares, limits, and reservations—and their impact on performance and VSWP file size. Rick explains exactly what happens when virtual machines compete for resources, the role of swap files, and how resource controls help automate allocation.
In chapter 2, Rick shows how to manage performance with resource pools, including child pools. He explains the impact a reservation has on resource pools, and includes a demo on creating and configuring a resource pool. Chapter 3 is an overview of the vFlash architecture for leveraging SSD resources. Watch this chapter to learn how to configure vFlash reservations and to assign a reservation to a VM.
Note: This course maps to the Administer and Manage vSphere 6.x Resources domain of the vSphere Certified Professional 6—Data Center Virtualization (VCP6DCV) exam.
- Allocating memory and CPU
- Using ESXTOP
- Configuring reservations, limits, and shares
- Managing performance with resource pools
- Creating child and tiered resource pools
- Leveraging SSD resources with vFlash