vSphere DRS Design for the Management Domain
vSphere Distributed Resource Scheduling (vSphere DRS) provides load balancing in a cluster by migrating workloads from heavily loaded ESXi hosts to ESXi hosts with more available resources in the cluster.
Automation Mode | Description |
|---|---|
Manual | vSphere DRS provides recommendations but an administrator must confirm the changes. |
Partially Automated |
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Fully Automated | vSphere DRS automatically migrates virtual machines to fulfill certain criteria and automatically places workloads onto appropriate hosts at power-on operations. |
When using two availability zones, create VM-Host group affinity rules for the initial placement of virtual machines. These affinity rules ensure that virtual machines run in a single availability zone unless an outage event occurs. In this way, you avoid unnecessary vSphere vMotion migrations of virtual machines between availability zones.
Decision ID | Design Decision | Design Justification | Design Implication |
|---|---|---|---|
VCF-MGMT-VCS-CLS-014 | Enable vSphere DRS on all clusters, using the default fully automated mode with medium threshold. | Provides the best trade-off between load balancing and unnecessary migrations with vSphere vMotion. | If a vCenter Server outage occurs, the mapping from virtual machines to ESXi hosts might be difficult to determine. |
Decision ID | Design Decision | Design Justification | Design Implication |
|---|---|---|---|
VCF-MGMT-VCS-CLS-015 | Create a host group for each availability zone and add the ESXi hosts in the zone to the respective group. | Makes it easier to manage which virtual machines run in which availability zone. | You must create and maintain VM-Host DRS group rules. |
VCF-MGMT-VCS-CLS-016 | Create a virtual machine group for each availability zone and add the VMs in the zone to the respective group. | Ensures that virtual machines are located only in the assigned availability zone to avoid unnecessary vSphere vMotion migrations. | You must add virtual machines to the allocated group manually. |
VCF-MGMT-VCS-CLS-017 | Create a should-run VM-Host affinity rule to run each group of virtual machines on the respective group of hosts in the same availability zone. | Ensures that virtual machines are located only in the assigned availability zone to avoid unnecessary vSphere vMotion migrations. | You must manually create the rules. |