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
The VMM for each virtual machine maintains a mapping from the guest operating system's physical
memory pages to the physical memory pages on the underlying machine. (VMware refers to the
underlying host physical pages as “machine” pages and the guest operating system’s physical pages as
“physical” pages.)
Each virtual machine sees a contiguous, zero-based, addressable physical memory space. The
underlying machine memory on the server used by each virtual machine is not necessarily contiguous.
The guest virtual to guest physical addresses are managed by the guest operating system. The
hypervisor is only responsible for translating the guest physical addresses to machine addresses.
Hardware-assisted memory virtualization utilizes the hardware facility to generate the combined mappings
with the guest's page tables and the nested page tables maintained by the hypervisor.
The diagram illustrates the ESXi implementation of memory virtualization.
Figure 5‑1. ESXi Memory Mapping
virtual machine
1
guest virtual memory
guest physical memory
machine memory
a b
a
a b b c
b
c b
b c
virtual machine
2
n
The boxes represent pages, and the arrows show the different memory mappings.
n
The arrows from guest virtual memory to guest physical memory show the mapping maintained by
the page tables in the guest operating system. (The mapping from virtual memory to linear memory
for x86-architecture processors is not shown.)
n
The arrows from guest physical memory to machine memory show the mapping maintained by the
VMM.
n
The dashed arrows show the mapping from guest virtual memory to machine memory in the shadow
page tables also maintained by the VMM. The underlying processor running the virtual machine uses
the shadow page table mappings.
Hardware-Assisted Memory Virtualization
Some CPUs, such as AMD SVM-V and the Intel Xeon 5500 series, provide hardware support for memory
virtualization by using two layers of page tables.
Note In this topic, "Memory" can refer to physical RAM or Persistent Memory.
vSphere Resource Management
VMware, Inc. 31