Planning for performance
As you plan your IBM® Power® Virtualization Center environment, ensure that you adhere to the recommended hardware and software minimums and maximums to achieve the best possible performance.
- Installing other software
- It is recommended that PowerVC is the only server application hosted on the virtual machine. However, PowerVC can generally coexist with other software
on the same instance, assuming that there is no resource or dependency conflict between PowerVC and the other software. Potential
conflicts include port contention, user namespace, file system capacity, firewall settings, and so
on. It is not recommended that you version lock any RPMs except when directed to do so by IBM support.
You should also consider performance implications to PowerVC and to the other software when installing other software on the same instance. For example, PowerVC memory usage may grow and cause problems with applications that coexist with PowerVC.
PowerVC resource requirements are sized assuming that PowerVC is the only workload that is running on the management instance. If other applications are using resources, adjust the sizing accordingly.
The following table lists some additional performance and scale considerations to observe to manage your PowerVC configuration with optimal performance.
Item | Requirement |
---|---|
Hardware and software requirements |
Ensure that the hardware and software in your environment meets the requirements that are documented for PowerVC. |
Maximum number of hosts and virtual machines (HMC) |
|
Maximum number of hosts and virtual machines (NovaLink) |
|
Mixed HMC and NovaLink scaling limits |
When your environment consists of both HMC-managed and NovaLink-managed hosts
|
Maximum number of virtual machines for each SAN Volume Controller |
|
Maximum number of virtual resources |
It is recommended that you configure the maximum number of virtual resources (virtual adapters) for the Virtual I/O Server to be at least three times the number of virtual machines that you plan to deploy on the host. This should enable you to have sufficient resources available on your hosts as you create and migrate virtual machines throughout your environment. |
Number of concurrent deployment operations | PowerVC has
the following limits on deployments:
|
Maximum number of concurrent migrations | You cannot exceed the maximum number of concurrent migrations designated for the source and destination hosts. The maximum number of concurrent migrations depends on the number of migrations supported by the Virtual I/O Servers that are associated with each host. |
Maximum number of concurrent operations supported for import and export of images | PowerVC
supports 4 concurrent image export or import operations. While performing image import or
export operations, make sure the following conditions are met:
|
Size of the Virtual I/O Server partition |
Use the Virtual I/O Server Performance Advisor tool to ensure that the Virtual I/O Server partition is properly sized. |
Maximum number of displayed images |
The PowerVC user interface displays a maximum of 400 images. So, if you have more than 400 images, you can work with only a subset of them on the PowerVC user interface. |
Number of concurrent virtual machine deletion operations |
When you delete virtual machines on multiple hosts, run the operations concurrently across the hosts. It is recommended that you do not exceed 50 concurrent delete operations. |
Maximum number of storage volumes |
For optimal performance, it is recommended that you use PowerVC to manage at most 10,000 storage volumes, with at most 128 volumes per virtual machine. When using an IPG in a storage connectivity group, the number of volumes attached to a virtual machine can scale more than 128 volume attachments. Refer to this topic for information on limits and restrictions for supported storage providers: Planning for storage providers. To overcome limits for a storage provider, use multiple storage providers. Note: For NovaLink, you can deploy an image that has at most
25 volumes. Additionally, you can capture at most 25 volumes when you capture a virtual
machine.
A single instance of an IBM XIV® storage system can attach up to 511 volumes per host mapping. |
Networking name resolution | For Virtual I/O Server
instances that do not have IPv6 configured, avoid overhead by configuring them to return only IPv4
addresses. To do this, specify the following line in the Virtual I/O Server
/etc/netsvc.conf file: . |