1.6.4 – Describe vSphere High Availability
Provides a base level of protection for your VMs by restarting VMs if a host fails and enables a collection of ESXi hosts to work together to provide workload availability. When vSphere HA is activated, an HA agent is installed on each host in the cluster. These agents communicate with each other to determine which […]
1.6.3 – Describe how Distributed Resource Scheduler (DRS) scores virtual machines
The VM DRS score is a metric that tracks a VMs execution efficiency on a given host. The cluster DRS score is a weighted average of the VM DRS scores of all powered on VMs in the cluster. The score is calculated every minute and if another host can provide a better score for the […]
1.6.2 – Describe vSphere Enhanced vMotion Compatibility (EVC)
EVC prevents vMotion migrations from failing because of incompatible CPU’s and works at the cluster level, using CPU baselines to configure all processors in the cluster that are activated for EVC. It ensures that all hosts in a cluster present the same CPU features to the VM stack, even if the CPU differs from each […]
1.6.1 – Describe Distributed Resource Scheduler (DRS)
DRS improves resource allocation across all hosts in a cluster. It aggregates computing capacity across a collection of servers into logical resource pools. It allows for automatic placements of workloads in a cluster and to ensure that virtual workloads are “happy”. You also get control of the automation level and you can configure affinity and […]
1.6 – Describe ESXi cluster concepts
A cluster is a collection of ESXi hosts and associated VMs with shared resources and a shared management interface. A cluster shares physical resources between a group of ESXi hosts. Vcenter server manages cluster resources as a single pool of resources. Clusters can contain up to 96 ESXi hosts. Clusters can be created based on […]
1.5 – Describe instant clone architecture and use cases
Instant clone uses a copy-on-write architecture similar to that of containers, which means that an app running in a child VM tries to change a shared OS file, a copy of the shared file is created and stored in the child VM. All modifications inside the VM are isolated within the VM itself. Master VM: […]
1.4 – Differentiate between vSphere Network I/O Control (NIOC) and vSphere Storage I/O Control (SIOC)
NIOC is used for QoS on network traffic and is useful for vSAN when it shares the physical NIC with other traffic types. Reserves bandwidth for system traffic based on the capacity of the physical adapters on a host. Enabled fine-grained resource control at the VM network adapter level similar to the model that you use […]
1.3.4 – Describe basic storage concepts in K8s, vSAN and vSphere Virtual Volumes (vVols)
vSphere with Kubernetes will support up to three different types of storage: Ephemeral virtual disks Temporary storage, VD stores objects such as logs or other temporary data. Once the pod no longer exists, the disk is gone as well. It persists across restarts and each pod only has one disk Container Image Virtual Disk, when […]
1.3.3 – Describe storage policies
The policies control which type of storage is provided for the virtual machine and how the virtual machine is placed within storage. Storage policies define how objects that are included in a VM are stored. There are default storage policies but there also is the possibility to create your own storage policies. You apply the […]
1.3.2 – Explain the importance of advanced storage configuration (vSphere Storage APIs for Storage Awareness (VASA), vSphere Storage APIs Array Integration (VAAI), etc.)
vSphere Storage API’s Array Integration (VAAI) These are Hardware Acceleration API’s that help arrays to integrate with vSphere for offloading certain storage operation to an array. It reduces CPU overhead on a host. They also provide Array Thin Provisioning APIs which help to monitor space use on thin-provisioned storage arrays to prevent out-of-space conditions, and […]