In this article, we are going to understand the Existing vSphere DRS and the New DRS 2.0 which is introduced with vSphere 7.0.
Introduction
vSphere DRS is designed to aggregate computing capacity across a collection of ESXi hosts.
Some of the cluster features are:
- Setting the Automation Level.
- Setting Migration Threshold.
- Enable Predictive DRS.
- Setting affinity or anti-affinity rules (VM-VM, VM-Host).
- Setting a per-VM Automation Level (VM Overrides)
Predictive DRS – this can be enabled when paired with vRealize Operations Manager for greater DRS effectiveness (surge processing) when combined with vROPS.
The DRS load balancing algorithm runs every five (5) minutes under DRS 1.0. DRS performs calculations in preparation for VM migrations which use vSphere vMotion. Once DRS finds VM migrations which will improve the host load balance, DRS will act using vMotion to perform needed VM migrations.
DRS Status at cluster level can be seen in the Summary Tab:
New DRS 2.0
Many of the previous DRS features and capabilities are the same in DRS 2.0. The main difference is in the load balance frequency and DRS per-VM focus.
- Prior DRS releases used to focus to aggregate computing capacity on cluster load bases, however, in the new DRS 2.0 the focus has changed to an Individual VM base to ensure resource requirements are met.
- The vSphere DRS 2.0 load balancing algorithm runs every minute.
Internally it uses a placement decision tree to evaluate current performance, perform a what-if scenario on a different compatible host, check the cost of the VM migration and then perform a vMotion to the new host if the VM will run more efficiently. The new focus of these calculations is for the highest VM DRS score – the highest instance that the VM’s resource requirements are being met.
DRS 2.0 has a New view and it can be accessed from the Summary Tab:
VM DRS Score is a new metric tracking VM execution efficiency on a given host – the frequency that the VM is reported having resource requirements met.
DRS Score: The Execution efficiency of this virtual machine. values closed to 0% indicate severe resource contention while values close to 100% indicate mild to no resource contention. DRS will try to maximize the execution efficiency of each virtual machine in the cluster while ensuring fairness in resource allocation of the Virtual Machine.
Important: Due to the new focus on VM DRS Score, there will likely be a greater number of vMotions initially once vSphere DRS 2.0 is enabled. This is due to the need to normalize the cluster – to ensure VMs have the resources they need regardless of which individual host they are placed on.
On the vSphere DRS 2.0 View, there are links toward the bottom left of the Screen: VIEW ALL VMS
The VIEW ALL VMS link actually takes you to the new VM DRS Score List.
vSphere DRS 2.0 has a new page to provide a listing of the VM DRS Scores and more detailed metrics regarding all cluster VMs. A VM DRS Score is computed from an individual VM’s CPU, memory and network metrics (aka VM goodness).
These metrics can be extremely useful in determining which hosts are experiencing resource contention and of what type.
Troubleshooting
For troubleshooting you can review the logs below:
/storage/log/vmware/vsphere-ui/logs/*.log | vsphere-ui service logs |
/storage/log/vmware/vsphere-ui/logs/ | vsphere_client_virgo.log |
/var/log/vmkernel.log | ESXi Vmkernel Logs |
/var/log/vmware/vpxd/vpxd.log | vCenter Server Logs |
For More information on the What’s New in vSphere 7.0 Please Visit: https://knowitlikepro.com/category/vmware/whats-new-in-vsphere-7-0/