Performance of vSphere 4.1 features emerge: Scalable vMotion, Wide VM Numa, Memory Compression, Storage I/O Control and others

Posted by Staff   |   Thursday, June 3rd, 2010   |  

After unveiling the list of features that will appear in the next major release of the VMware vSphere platform (currently numbered 4.1, but likely to change in 4.5 to align with the upcoming release of View 4.5), can now share full details about the performance improvements introduced by some of them, like Scalable vMotion, Wide VM Numa, Memory Compression and others.

Let’s start with the new configuration limits that can vSphere 4.1 can reach:

  • 3,000 virtual machines per cluster (compared to 1,280 in vSphere 4.0)
  • 1,000 hosts per vCenter Server (compared to 300)
  • 15,000 registered VMs per vCenter Server (compared to 4,500)
  • 10,000 concurrently powered-on VMs per vCenter Server (compared to 3,000)
  • 120 concurrent Virtual Infrastructure Clients per vCenter Server (compared to 30)
  • 500 hosts per virtual Datacenter object (compared to 100)
  • 5,000 virtual machines per virtual Datacenter object (compared to 2,500)

The hostd footprint and memory consumption (down by 40%) has been greatly reduced, speeding up some operations by a factor of 3x.

Scalable vMotion
vSphere 4.1 supports up to 8 concurrent virtual machines live migrations and VMware seems to have renamed the feature in Scalable vMotion.
The engine has been significantly reworked to reach a throughput of 8GB/sec on a 10GbE link, 3 times the performance scored in version 4.0.

Wide VM Numa
The vSphere 4.1 NUMA scheduler has been reworked to improve performance when a certain virtual machine needs more cores than the ones available on a certain NUMA node, assuming that the server has a large number of NUMA nodes.
Depending on workloads and configurations, the performance improvement is up to 7%.

Transparent Memory Compression
vSphere 4.1 introduces a new memory over-commit technique called Transparent Memory Compression (TMC) that compresses on the fly the virtual pages that should be otherwise swapped on disk.
Each virtual machine has a compression cache where vSphere can store compressed pages of 2KB or smaller size.

TMC is enabled by default on ESX/ESXi 4.1 hosts but the administrator can define the compression cache limits or disable TMC completely.

This results in a performance regain of 15% when there’s a fair amount of memory over-commitment and a regain of 25% in case of heavy over-commitment.


Storage I/O Control
vSphere 4.1 introduces the capability to define quality of service prioritization for the I/O activity on a single host or a cluster of hosts.
The prioritization, which can be enable or disable on specific datastores, is enforced through shares and limits.

The ESX/ESXi hosts monitors the latency in communication with the datastore of choice. As soon such latency exceeds a defined threshold the datastore is considered congested.
At that point all VMs accessing that datastore are prioritized according to their defined shares.
The administrator can even define the amount of I/O operations per second (IOPS) that each virtual machine can reach.

Here’s an example:

vSphere41_StorageIOControl VMware reports an improvement up to 36% in certain scenarios.


Additional performance enhancements
vSphere 4.1 introduces additional improvements in other areas like Storage vMotion, thanks to the support for 8GB Fibre Channel HBAs.
VMware reports a performance improvement (in terms of IOPS) of 50% compared to 4GB FC HBAs and five times better performance in throughput usage.

Support for NFS storage has been improved too, and it now features up to 15% reduction in CPU cost for read & writes as well as up to 15% improvement in throughput usage.

iSCSI support has been improved too, with the new support for iSCSI TCP Offload Engine (TOE) network interface cards.
VMware reports a performance improvement of up to 89% in CPU read cost and 83% in CPU write cost.

vSphere 4.1 has additional new capabilities for its networking layer with the introduction of support for Large Receive Offload (LRO), which allows to receive network packets larger than the MTU size.
This is useful only for Linux guest operating systems that support LRO.
LRO support translates in a 5-30% performance improvement in throughput usage and 40-60% decrease in CPU cost depending on workloads.

vSphere 4.1 also introduces asynchronous transmission of network packets through a new TX Wordlets scheduler.
It translates into a throughput improvement of 2X for intra-VMs traffic and up to 10% throughput improvement for VM-to-host traffic.

Last but not least, vSphere 4.1 also introduces better performance for VDI when used in conjunction with View.
The creation of new virtual desktops now is 60% faster and their power on timing is 3.4 times faster.


blog comments powered by Disqus Newest articles
Release: VMware vRealize Log Insight 4.5

June 13th, 2017

Log Insight is a log aggregation, management and analysis tool, that VMware first introduced in 2013 and considered a competitor of Splunk.
Yesterday VMware announced the release of version 4.5, available for…

Release: VMware vRealize Automation 7.3

June 6th, 2017

Today VMware announced the latest release of its cloud management platform vRealize Automation, former vCloud Automation Center.
VMware vRealize Automation 7.3 release notes can be found at this link.


Paper: Introducing the NSX-T Platform

February 9th, 2017

“We see greater potential strategic opportunity in NSX over the next decade than our franchise product vSphere has had for the past decade.”
said VMware’s CEO Pat Gelsinger talking about…

Paper: VMware vSphere Virtual Machine Encryption Performance

November 22nd, 2016

Encryption of virtual machines is something that has been requested for years by the security community. VMware continued to postpone its implementation due to the negative operational impact that many…

Quest Software leaves Dell

November 1st, 2016

In September 2012 Dell announced to have completed the acquisition of Quest Software, a Californian company with an history in systems management, security, business intelligence and, falling back in our…

Citrix announces Q3 2016 results

October 21st, 2016

Citrix announced its financial results for third quarter 2016.
The revenues for the second quarter were $841 million for an increase of 3% compared to Q3 2015.
Net income was $132…

Release: VMware vSphere 6.5 & Virtual SAN 6.5

October 19th, 2016

2016 edition of VMworld US has been quite turbulent, on the other hand during VMworld Europe, happening these days in Barcelona, the company announced a few more products for the…

Release: VMware vRealize Log Insight 4.0

October 18th, 2016

Log Insight is a log aggregation, management and analisys tool, that VMware first introduced in 2013 and now is usually compared with Splunk.
Yesterday VMware announced Log Insight’s new major…

Release: Windows Server 2016 with support for Window Server & Hyper-V containers

October 13th, 2016

Yesterday Microsoft announced the general availability of Windows Server 2016 which the company defines as a cloud-ready OS.
Beside fancy definitions, one of the most relevant perks of this release…

Release: Oracle VM 3.4.2

September 22nd, 2016

During Oracle OpenWorld 2016 the company released version 3.4.2 of its enterprise virtualization solution.
Oracle VM is available for both x86 and SPARC based processor architectures and uses the Xen hypervisor…

VMworld US 2016 Wrap-up

September 1st, 2016

Today was the last day of VMware’s flagship conference VMworld in Las Vegas, an highly controversial edition which left a good chunk of the audience disoriented if not properly disappointed….

Gartner releases its Magic Quadrant for Cloud Infrastructure as a Service for 2016

August 11th, 2016

Last week Gartner updated its Magic Quadrant for Cloud Infrastructure as a Service (IaaS) for the year 2016. The Magic Quadrant for the year 2015 was released in May last year…

Release: Ansible Tower 3 by Red Hat

August 2nd, 2016

Ansible is one of the four main players in the automation market, younger then the well known Chef and Puppet, has been launched in 2013 in Durham, N.C. and acquired…

IBM announces earnings for Q2 2016

July 19th, 2016

Yesterday IBM announced its results for Q2 2016.

If we compare with the same quarter in 2015 earnings per share, from continuing operations, decreased 22%. Net income, from continuing operations,…

Monthly Archive