Memory allocated to a VMware Virtual Machine (VM) is not a guarentee of resources. Understand resource contention and its imapact on a vSphere ESXi host.
- [Voiceover] In this video,…I'll explain how memory resources…are allocated to virtual machines.…When you create a virtual machine,…you'll allocate a certain amount of memory to it.…The amount of memory required varies…from one virtual machine to another.…The applications and operation system…running on the virtual machine…will determine how much memory it consumes.…And when you allocate memory to a virtual machine,…you're not actually guaranteeing any physical resources.…Memory is thin provisioned,…meaning that the virtual machine…will only consume the memory…that it truly requires.…
For example, if a virtual machine is configured…with two gigs of memory,…it may actually only consume 500 megabytes.…So how much memory…should we actually give our virtual machines?…The answer is simple.…Give them as much memory as they need to function properly…and no more.…Overprovisioning virtual machines…with excessive memory…can result in poorer performance.…Let's think about a parking lot as an example.…Let's say that we're painting lines for parking spots.…
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