6.7
Table Of Contents
- vSphere Resource Management
- Contents
- About vSphere Resource Management
- Getting Started with Resource Management
- Configuring Resource Allocation Settings
- CPU Virtualization Basics
- Administering CPU Resources
- Memory Virtualization Basics
- Administering Memory Resources
- Persistent Memory
- Configuring Virtual Graphics
- Managing Storage I/O Resources
- Managing Resource Pools
- Creating a DRS Cluster
- Using DRS Clusters to Manage Resources
- Creating a Datastore Cluster
- Initial Placement and Ongoing Balancing
- Storage Migration Recommendations
- Create a Datastore Cluster
- Enable and Disable Storage DRS
- Set the Automation Level for Datastore Clusters
- Setting the Aggressiveness Level for Storage DRS
- Datastore Cluster Requirements
- Adding and Removing Datastores from a Datastore Cluster
- Using Datastore Clusters to Manage Storage Resources
- Using NUMA Systems with ESXi
- Advanced Attributes
- Fault Definitions
- Virtual Machine is Pinned
- Virtual Machine not Compatible with any Host
- VM/VM DRS Rule Violated when Moving to another Host
- Host Incompatible with Virtual Machine
- Host Has Virtual Machine That Violates VM/VM DRS Rules
- Host has Insufficient Capacity for Virtual Machine
- Host in Incorrect State
- Host Has Insufficient Number of Physical CPUs for Virtual Machine
- Host has Insufficient Capacity for Each Virtual Machine CPU
- The Virtual Machine Is in vMotion
- No Active Host in Cluster
- Insufficient Resources
- Insufficient Resources to Satisfy Configured Failover Level for HA
- No Compatible Hard Affinity Host
- No Compatible Soft Affinity Host
- Soft Rule Violation Correction Disallowed
- Soft Rule Violation Correction Impact
- DRS Troubleshooting Information
- Cluster Problems
- Load Imbalance on Cluster
- Cluster is Yellow
- Cluster is Red Because of Inconsistent Resource Pool
- Cluster Is Red Because Failover Capacity Is Violated
- No Hosts are Powered Off When Total Cluster Load is Low
- Hosts Are Powered-off When Total Cluster Load Is High
- DRS Seldom or Never Performs vMotion Migrations
- Host Problems
- DRS Recommends Host Be Powered on to Increase Capacity When Total Cluster Load Is Low
- Total Cluster Load Is High
- Total Cluster Load Is Low
- DRS Does Not Evacuate a Host Requested to Enter Maintenance or Standby Mode
- DRS Does Not Move Any Virtual Machines onto a Host
- DRS Does Not Move Any Virtual Machines from a Host
- Virtual Machine Problems
- Cluster Problems
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Datastore Cluster Requirements
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Adding and Removing Datastores from a Datastore Cluster
Initial Placement and Ongoing Balancing
Storage DRS provides initial placement and ongoing balancing recommendations to datastores in a
Storage DRS-enabled datastore cluster.
Initial placement occurs when Storage DRS selects a datastore within a datastore cluster on which to
place a virtual machine disk. This happens when the virtual machine is being created or cloned, when a
virtual machine disk is being migrated to another datastore cluster, or when you add a disk to an existing
virtual machine.
Initial placement recommendations are made in accordance with space constraints and with respect to
the goals of space and I/O load balancing. These goals aim to minimize the risk of over-provisioning one
datastore, storage I/O bottlenecks, and performance impact on virtual machines.
Storage DRS is invoked at the configured frequency (by default, every eight hours) or when one or more
datastores in a datastore cluster exceeds the user-configurable space utilization thresholds. When
Storage DRS is invoked, it checks each datastore's space utilization and I/O latency values against the
threshold. For I/O latency, Storage DRS uses the 90th percentile I/O latency measured over the course of
a day to compare against the threshold.
Storage Migration Recommendations
vCenter Server displays migration recommendations on the Storage DRS Recommendations page for
datastore clusters that have manual automation mode.
The system provides as many recommendations as necessary to enforce Storage DRS rules and to
balance the space and I/O resources of the datastore cluster. Each recommendation includes the virtual
machine name, the virtual disk name, the name of the datastore cluster, the source datastore, the
destination datastore, and a reason for the recommendation.
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Balance datastore space use
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Balance datastore I/O load
Storage DRS makes mandatory recommendations for migration in the following situations:
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The datastore is out of space.
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Anti-affinity or affinity rules are being violated.
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The datastore is entering maintenance mode and must be evacuated.
In addition, optional recommendations are made when a datastore is close to running out of space or
when adjustments should be made for space and I/O load balancing.
Storage DRS considers moving virtual machines that are powered off or powered on for space balancing.
Storage DRS includes powered-off virtual machines with snapshots in these considerations.
vSphere Resource Management
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