VMware has released a paper titled: “The CPU Scheduler in VMware vSphere 5.1“. The paper which contains 26 pages provides detailed explanations of ESXi CPU scheduling policies to help vSphere users who want to understand how virtual machines are scheduled.
The CPU scheduler is an essential component of vSphere 5.x. All workloads running in a virtual machine must be scheduled for execution and the CPU scheduler handles this task with policies that maintain fairness, throughput, responsiveness, and scalability of CPU resources.
The paper contains the following sections:
- Executive Summary
- CPU Scheduler Overview
- Proportional Share-Based Algorithm
- Relaxed Co-Scheduling
- Load Balancing
- Policy on Hyper-Threading
- NUMA Scheduling Policy
The ESXi CPU scheduler achieves fair distribution of compute resources among many virtual machines without compromising system throughput and responsiveness. Relaxed co-scheduling is a salient feature that enables both correct and efficient execution of guest instructions with low overhead. The ESXi CPU scheduler is highly scalable and supports very big systems and wide virtual machine.
vSphere 5.1 optimizes the load-balancing algorithm introduced in 5.0. It results in noticeable reductions in CPU scheduling overhead. A policy change on hyper-threaded systems enables out-of-the-box performance of 5.1 exceeding that of a tuned version of vSphere 4.1. No special tuning is required to achieve the best performance for most common application workloads. The irtual NUMA feature introduced in 5.0 can significantly improve performance of workloads that are optimized for a NUMA environment. With vNUMA, virtual machines of any size can display optimal performance on a NUMA system. The vNUMA feature is shown to significantly improve the performance of SPEC OMP workloads. Such improvement closes the performance gap between the virtual and the native environment for high-performance-computing (HPC) workloads.
blog comments powered by Disqus
virtualization.info Newest articles
February 1st, 2016
During Ignite 2015, back in September, Microsoft announced Microsoft Azure Stack as the building block for its hybrid cloud strategy.
What Microsoft is saying with this move is that, despite…
January 14th, 2016
Ansible is an IT automation tool especially popular within the developers’ community, thanks to its simplicity and agentless nature.
Three months away from its acquisition by Red Hat the company announced…
December 23rd, 2015
Nutanix is a provider of converged infrastructure, basically a physical server containing both compute and storage driven by an Installed Hypervisor of choice, this server, called a node can…
December 23rd, 2015
Last week VMware finally completed the first major update of VMware vRealize Suite, its well known cloud management solution, releasing in GA both vRealize Automation 7 and vRealize Business Standard…
December 15th, 2015
virtualization.info has been following Virtualization Matrix since its early steps and we recently wrote about its crowdsourced-powered heir: WhatMatrix.
Today we are happy to report that its community, formed…
November 18th, 2015
As you may have heard, Microsoft recently announced its “historical” partnership with Red Hat, something that a number of analysts already claimed as a milestone for both companies but especially for…
October 16th, 2015
Today Red Hat announced that it has signed a definitive agreement to acquire Ansible, provider of an IT automation tool popular especially within the developers’ community.
The acquisition is rumored…
October 12th, 2015
Dell today announced that it signed a definitive agreement to acquire EMC Corporation for a total of $67 billion, making it the largest ever acquisition in the technology industry so…
October 2nd, 2015
Red Hat announced its financial results for the second quarter of fiscal year 2016.
Total revenue for the second quarter ended Augus 31, 2015 was $504 million, with an increase…
September 21st, 2015
Citrix on its website announced that it started the End-of-Life process of Citrix XenClient Enterprise, the end of life date will be December 12, 2016.
XenClient consists of two technologies,…
September 9th, 2015
Altaro Software, company specialized in backup for virtualized environments, specifically Microsoft Hyper-V, announced the release of Altaro VM Backup, previously known as Altaro Hyper-V Backup, rebranded to introduce VMware…
September 9th, 2015
CloudPhysics, provider of a SaaS performance and capacity analytics solution, announced to have released a new version of its SaaS offering allowing now VMware users to preempt and eliminate…
September 2nd, 2015
During its annual VMworld conference held between August 30 and September 3 in San Fransicso VMware made several announcements. During the keynote on Monday several data center related announcements and…
August 25th, 2015
VMware today released version 12 of its type-2 client hypervisor products for Microsoft Windows: Workstation Pro and Player and version 8 of its client hypervisor products for Mac OSX: Fusion….