6.5.1
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
- 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
- Index
Host-local swap is now enabled for the standalone host.
Swap Space and Memory Overcommitment
You must reserve swap space for any unreserved virtual machine memory (the dierence between the
reservation and the congured memory size) on per-virtual machine swap les.
This swap reservation is required to ensure that the ESXi host is able to preserve virtual machine memory
under any circumstances. In practice, only a small fraction of the host-level swap space might be used.
If you are overcommiing memory with ESXi, to support the intra-guest swapping induced by ballooning,
ensure that your guest operating systems also have sucient swap space. This guest-level swap space must
be greater than or equal to the dierence between the virtual machine’s congured memory size and its
Reservation.
C If memory is overcommied, and the guest operating system is congured with insucient swap
space, the guest operating system in the virtual machine can fail.
To prevent virtual machine failure, increase the size of the swap space in your virtual machines.
n
Windows guest operating systems— Windows operating systems refer to their swap space as paging
les. Some Windows operating systems try to increase the size of paging les automatically, if there is
sucient free disk space.
See your Microsoft Windows documentation or search the Windows help les for “paging les.” Follow
the instructions for changing the size of the virtual memory paging le.
n
Linux guest operating system — Linux operating systems refer to their swap space as swap les. For
information on increasing swap les, see the following Linux man pages:
n
mkswap — Sets up a Linux swap area.
n
swapon — Enables devices and les for paging and swapping.
Guest operating systems with a lot of memory and small virtual disks (for example, a virtual machine with
8GB RAM and a 2GB virtual disk) are more susceptible to having insucient swap space.
N Do not store swap les on thin-provisioned LUNs. Running a virtual machine with a swap le that is
stored on a thin-provisioned LUN can cause swap le growth failure, which can lead to termination of the
virtual machine.
When you create a large swap le (for example, larger than 100GB), the amount of time it takes for the
virtual machine to power on can increase signicantly. To avoid this, set a high reservation for large virtual
machines.
You can also place swap les on less costly storage using host-local swap les.
Configure Virtual Machine Swapfile Properties for the Host
Congure a swaple location for the host to determine the default location for virtual machine swaples in
the vSphere Web Client.
By default, swaples for a virtual machine are located on a datastore in the folder that contains the other
virtual machine les. However, you can congure your host to place virtual machine swaples on an
alternative datastore.
You can use this option to place virtual machine swaples on lower-cost or higher-performance storage. You
can also override this host-level seing for individual virtual machines.
vSphere Resource Management
38 VMware, Inc.