My friend Fred has a VMware infrastructure and lately, he started running out of Compute resources. I advised him to get additional hosts to beef up his resources and increase his availability posture. Everything went perfectly as far as adding the host to his vCenter was concerned. He started having an issue with vMotion.
vMotion is a technology that migrates Virtual Machines (VMs) between servers to balance resources or to free up a host for maintenance purposes.
The issue Fred was having is that the CPU generation between the new servers and the existing ones was different. Whether you use Intel or AMD CPUs, they were built within a certain generation that determines how the processor operates. If you are using CPUs that are not in the same generation, migrating workloads from one Gen to the other one while the VM is running may pose compute issues. This is why Fred started getting an error. This is the error he started receiving whenever he tried to perform vMotion to balance resource utilization.
“The target host does not support the virtual machine’s current hardware requirements. Use a cluster with Enhanced vMotion Compatibility (EVC) enabled to create a uniform set of CPU features across the cluster, or use per-VM EVC for a consistent set of CPU features for a virtual machine and allow the virtual machine to be moved to a host capable of supporting that set of CPU features. See KB article 1003212 for cluster EVC information.” –Some lines were omitted for brevity.
From the above output, it is obvious that Fred needed to configure an additional feature of VMware for his vMotion to work. That feature is EVC (Enhanced vMotion Compatibility).
What is EVC?
EVC is a feature that is configured in the vCenter Server at the cluster level. EVC ensures vMotion compatibility for all your hosts in a vSphere cluster. When this is configured, it ensures that all hosts in a cluster present the same CPU features to virtual machines, even if the actual CPUs on the hosts are not of the same generation (e.g. Skylake, Broadwell, Haswell, Ivy Bridge, Sandy Bride etc).
All the host processors in the cluster present the features of the baseline processor (the earliest generation CPU in the cluster) EVC uses AMD-V Extended Migration technology (for AMD hosts) and Intel FlexMigration technology (for Intel hosts) to mask processor features so that hosts can present the feature set of the earlier generation of processors.
Are there serious drawbacks with limiting yourself to an older version of CPU using EVC? Well, when you enable EVC on your vSphere cluster, it does not prevent a VM from:
Simply put, EVC does not prevent virtual machines from accessing hidden CPU features.
Keep in mind:
To turn ON EVC for existing infrastructures, you might have to shut down all Virtual Machines running on the cluster. Most production environments cannot afford such downtimes, and this creates problems when vMotion becomes necessary. The advice is to always configure EVC during cluster creation during the initial setup of the virtual infrastructure.
Per-VM EVC.
Another great feature is to enable EVC, not at the ESXi host level but the VM level. When per-VM EVC is configured, it enables the migration of the virtual machines beyond the cluster and across vCenter Server systems and data centers that have different processors (e.g. VMware on AWS).
With Per-VM EVC, the EVC mode becomes an attribute of the virtual machine rather than the specific processor generation it happens to be booted on in the cluster. VMware introduced per-VM EVC starting from vSphere version 6.7 and it requires virtual machine hardware version 14 or later for the feature to work properly.
The per-VM EVC mode determines the set of host CPU features that a virtual machine requires to power ON and migrate.
Please note, per-VM EVC is disabled by default on all virtual machines. To enable, disable or change the EVC mode of a VM, it must be shut down first. Similar to the host or cluster level EVC, Lowering the EVC baseline increases the CPU compatibility of the virtual machine.
Cluster level EVC vs Per-VM EVC
There are several differences between the way the EVC feature works at the host or cluster level versus at the virtual machine level.
Let me give you an example: if you configure a cluster with the Intel “Merom” Generation EVC mode, you should not configure a virtual machine with any other Intel baseline feature set. All other sets contain more CPU features than the Intel “Merom” Generation feature set and as a result of such configuration, the virtual machine would certainly fail to power ON.
Summary
It is important to ensure all VMs are able to migrate without downtime (using vMotion). EVC provides compatibility across CPUs of various generations, unleashing the power promised by virtualization (hardware-agnosticism). With the new version of VMware providing the ability to do EVC at the VM-level, we now have more flexibility to enable the hybrid-cloud infrastructure.
Apotica deploys a large portfolio of Next-Generation technologies and is uniquely positioned to advise on the next steps to help with your data center strategy. You can request a free consultation here. To enquire about any equipment or software, call us on +233.54.431.5710 or write to sales@apotica.net.
Apotica is headquartered in Accra, Ghana and brings together the best information and communications technologies to help clients grow, compete and serve their customers better. Apotica is an ISO 27001 and 9001 Certified Organization.
Matilda, a Chartered Accountant, joined Apotica in May 2023. With over 12 years of experience in banking, insurance, pensions, accounting and finance, she is responsible for the company’s financial control, strategic planning, management reporting, and overall financial performance.
She holds a BSc degree in Business Administration (Accounting) from the University of Ghana Business School and an MSc in Accounting and Finance from the same institution. Matilda is also a member of the Institute of Chartered Accountants, Ghana.
Matilda has attended the Executive Education course in Strategic Management at the Maastricht School of Management in the Netherlands and participated in other leadership seminars around the world.
Peniel Korley is Head of Marketing for Apotica, designing and implementing comprehensive marketing strategies to create awareness of the company’s business activities.
Peniel joined Apotica in April 2019 and has helped build our market presence through an adept combination of traditional marketing and digital marketing techniques, executing and monitoring corporate promotion campaigns, and conducting market research to help us stay abreast of trends.
He earned a Bachelor’s degree in Economics from the University of Ghana and a Master of Business Administration degree in Marketing from the University of Ghana Business School. He’s a member of the Chartered Institute of Marketing, UK.
As Head of Projects, Sylvester Kyeremeh is responsible for coordinating people and processes to ensure that our client projects are delivered on time and produce the desired results. He leads this function within the confines of our quality management and information security management systems.
Sylvester joined Apotica in 2017 as a Systems Engineer, before moving on to join our project management practice a year later. His calm and collected approach to interpersonal engagements, impressive sense of planning, and excellent communication skills continue to receive the plaudits of our customers.
Sylvester received his B.S. degree in Computer Engineering from the Kwame Nkrumah University of Science & Technology. He’s a Certified Information Systems Auditor, a Cisco-certified professional, an ISO 27001 Lead Implementer, and a member of the Project Management Institute with PMP and Scrum Master qualifications.
At 25, Millicent is currently the youngest head of department at Apotica, taking up this role in August 2020. She’s responsible for managing all aspects of risk to the organization, employees, clients, assets, reputation, and interests of stakeholders. Millicent also works with the leadership of the organization to embed and maintain a risk-aware culture in the organization.
Before joining Apotica, she worked as a broadcast journalist at Radio Universe – a popular media house in Accra. Millicent holds a Bachelor’s degree in Psychology and has attended the Executive Education course in Personal Leadership at the Maastricht School of Management, Netherlands.
She’s a Certified Governance, Risk, and Compliance Professional (GRCP) and a qualified ISO 9001 Lead Implementer.
Elom Kutsienyo is the Chief Technology Officer at Apotica. A technology enthusiast and Apple nerd, he is responsible for the development and maintenance of our excellent technical services capabilities and enabling our engineering teams to become adept at industry best practices relating to enterprise solutions design, deployments, and support.
Since taking up the CTO role in August 2019, he has strategically grown our product offerings through strong channel partnerships with leading ICT vendors. Elom’s extensive experience in product sales, project management, service delivery, and field engineering also helps as he oversees company webinars, product demos, proof-of-value activities, and technical proposals for clients.
He holds a Bachelor’s degree in Telecom Engineering from Ghana Technology University College and has attained several professional qualifications including the coveted Cisco CCIE certification as well as certifications from Microsoft, VMware, NetApp, HPE, and Nutanix.
Clifford leads the Customer Experience practice at Apotica which encompasses our consulting, technology, support, and learning services.
Prior to his position at Apotica, Clifford was the senior manager of IT Infrastructure at Stanbic, a leading commercial bank in Ghana. He has also previously held roles in field engineering, service delivery, and customer support at organizations including Huawei, IBM, Tech Mahindra, and Zenith Bank.
Clifford is PMP-certified and holds a Bachelor’s in Information Technology, as well as several industry certifications from Microsoft, VMware, and Amazon.
Dzigbodi Amekoudi oversees company business in Benin and the countries in French West Africa. As Country Manager, his primary responsibility is business development, which involves helping to define and introduce the right go-to-market strategies and making sure our business operates profitably in the territory. He’s also responsible for establishing operating budgets and managing company employees in his region.
During his tenure, Dzigbodi has led Apotica’s expansion into other countries including Burkina Faso, Guinea Conakry, Mali, and Niger. Additionally, he works with our technical services leads to ensure successful post-sales delivery of customer projects.
Dzigbodi started his career in engineering and project management, before joining Apotica as a key accounts manager in January 2020.
He earned a Bachelor of Engineering degree in Telecommunications from Ghana Technology University College and a Master of Science degree in International Management from Franklin University Switzerland. He’s a member of the Chartered Institute of Marketing, UK.
Emmanuel Nketia is responsible for managing all sales functions at Apotica and oversees other departments, including marketing, operations, and client renewals. An excellent salesman and negotiator, he brings with him 20 years of experience in logistics, accounting, business development, and customer relationship management.
He earned a Bachelor of Science degree in Mathematics from Kwame Nkrumah University of Science & Technology. He’s also a member of the Chartered Institute of Marketing, UK, and an MBA Marketing candidate at the University of Ghana Business School.
Emmanuel has attended the Executive Education course in Strategic Management from the Maastricht School of Management in the Netherlands and participated in other leadership seminars in the USA.
At Apotica, we are on a mission to help clients grow and serve their customers better. As CEO, Felix Nkansah works closely with our Sales, Services, and Operations leadership to identify customer and industry transitions and determine our strategies to address them.
Felix joined Apotica in January 2017 and brings more than 18 years of experience across executive leadership, systems engineering, customer support, and sales functions with some regional conglomerates and information technology companies.
He has a background in computer science and holds expert-level professional certifications in networking, security, and systems design.