VMs Unevenly Distributed by DRS to High-Spec Hosts
Article ID: 447253
Updated On:
Products
Issue/Introduction
In a cluster with heterogeneous hosts (mixed hardware specifications), DRS disproportionately allocates and concentrates virtual machines on the higher-specification hosts.
Environment
VMware vCenter Server 8.x
VMware vCenter Server 9.x
Cause
Broadcom is aware of this issue and is working on a fix to be included in a future release.
Resolution
No effective workaround is available.
Additional Information
Consider aligning host specifications within each cluster, as recommended in the following documentation:
Performance Best Practices for VMware vSphere 8.0 Update 3
https://www.vmware.com/docs/vsphere-esxi-vcenter-server-80U3-performance-best-practices
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DRS Cluster Configuration Settings
When deciding which hosts to group into DRS clusters, try to choose hosts that are as homogeneous as
possible in terms of CPU and memory. This improves performance predictability and stability.
When heterogeneous systems have compatible CPUs, but have different CPU frequencies and/or
amounts of memory, DRS generally prefers to locate virtual machines on the systems with more memory
and higher CPU frequencies (all other things being equal), since those systems have more capacity to
accommodate peak loads.
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