Kubernetes vs VMWare VSphere

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In the world of virtualization, virtual machines and container technology are often seen as alternatives. However, hardware virtualization and containerization have different features and can even be integrated into working together. This article compares two of the biggest orchestration solutions, Kubernetes—for containers—and VMware vSphere—for Virtual Machines (VM). 

Containers vs Virtual Machines

Containers and virtual machines operate at different levels. Containers package and isolate the software at the operating system level. Virtual machines divide a physical server into different virtual servers, working at the hardware level. Typically, machine virtualization is a better fit for infrastructure-as-a-service, and containers work better for portable and modular software. However, the technologies are not substitutes for each other. Recently, vendors have been creating containers inside virtual machines to build a portable solution.

Machine virtualization and containerization technologies manage containers and virtual machines differently. The following sections will provide an overview of the two main orchestration platforms: Kubernetes and vSphere. 

What Is Kubernetes?

Kubernetes is a container orchestration platform that automates the management and deployment of software containers. Developed by Google, this open-source and free software is one of the main forces behind the worldwide adoption of container computing. 

To understand Kubernetes, we need first to understand containers. Containers are packaged software with the specific parts that run as self-contained units. This enables developers to move code across environments faster and with ease. For example, from development to production. 

Containers are lightweight, meaning they use little compute resources. That means that using containers enables companies to run more applications on one server. While a small company with a few software containers can manage with a container management application, the majority of organizations soon find themselves managing hundreds or thousands of containers. Doing this manually is complex and time-consuming.

 Kubernetes automates container management. Without Kubernetes, organizations need to manually update hundreds of containers with every new feature release. Automation with Kubernetes may include, for example, storing workloads across environments. In addition, you can scale apps up or down according to requirements.

 Kubernetes monitors the health of apps by rolling out changes progressively. If something goes wrong, the system rolls back the changes without killing all instances at the same time. The system can restart, create new, replace and reschedule failing containers or nodes. Users can configure the system to automatically kill non-responding containers. 

Pros and Cons of Kubernetes

Kubernetes was created by Google but now it is managed by the Cloud Native Computing Foundation, which is a vendor-agnostic organization. One of the main features of Kubernetes is that it can run anywhere: on-premises or in the cloud, thus preventing vendor lock-in.

The platform makes it easy to deploy and scale containerized apps. The scalability of Kubernetes allows organizations to run billions of containers. Supported by a large community of contributors, the platform gets updates and new features all the time. 

Pros of Kubernetes

• Broad adoption—the popularity of the software means there are frequent contributions from the community, faster development, and better maintainability. 
• Supporting tools and interfaces—Kubernetes makes it easy to integrate additional tools and interfaces for security, monitoring, networking or databases. For example, major databases are developing Helm charts (pre-packaged applications that can be deployed in a Kubernetes platform). 
• Multiple deployments and workloads options—Kubernetes offers API resources for running applications such as replicated apps, microservices, and stateful apps. 
• Built-in security—there are a number of security features included with Kubernetes such as Secrets API, which allows exposing sensitive information in a secure way. Other security features include role-based access control (RBAC) that enables users to manage access privileges. 
• Extensibility—users can extend Kubernetes with API resources and storage plugins. For instance, you can use scheduler extensions to extend the functionality of the Kubernetes scheduler. 
• Integration with major cloud providers—Kubernetes integrates the platform with the major cloud providers through a control feature called a cloud-controller-manager. You can use this manager to run multiple cloud checks and controls inside the Kubernetes clusters. 
• Open-source—Kubernetes’ popularity is partly due to its open-source nature, and today it boasts a large community of contributors that constantly improve and add features to the platform. 

Cons of Kubernetes

• Steep learning curve—developers often find that Kubernetes is not an easy platform to learn. However, it is doable thanks to a number of training courses offered by many reputable Kubernetes service providers. You find tutorials and courses online for any level.  
• Hard to configure manually—teams trying to install Kubernetes find that there are several components to configure separately to initialize the cluster. Some of the pre and post-installation tasks include configuring the high availability of masters and components, configuring multi-host networking and configuring security. This list of requirements makes Kubernetes hard to install and configure. Thankfully there are a number of solutions available that can make the installation and management of Kubernetes much easier. 

What Is VMWare vSphere?

A virtual machine is a self-contained operating environment. It works as if it is an individual computer. VMware vSphere is a server virtualization platform released by VMware. vSphere serves as a platform to implement and manage an infrastructure of virtual machines (VM) at scale. 

VMware vSphere translates server virtualization functions into a cloud computing virtualization operating system. Server virtualization is the process of partitioning a physical server into smaller virtual servers. This feature is commonly used in Web servers, in order to provide low-cost hosting services. Each virtual server runs its own operating system and can be rebooted independently. 

The ESXi feature is the center of the vSphere suite and provides the hypervisor technology that enables hardware virtualization. Hypervisors enable multiple operating systems to live on a single host. Each operating system gets dedicated resources, such as virtual memory and computing. The main advantage of ESXi is that it does not require a pre-existing operating system. It runs in the bare-metal server. The hypervisor creates a hardware, guest system and service console. 

Pros and Cons of VMWare vSphere

VMware VSphere has pros and cons as any software platform. Some of the advantages of using vSphere are its stability and reliability. In addition, it features a large documentation and online help. 

Some of the pros and cons mentioned by vSphere users are:

Pros

• Data recovery—it allows restoring deleted VM with just a few command-line tools. 
• Easy to increase the density of virtualized servers—this facilitates page and memory sharing.
• High availability—the system allows configuring redundant server pairs away from each other to achieve high availability. In case of a disaster or server failure, it is easy to bring the system up from another redundant server.
• Built-in security—virtual machines in vSphere are encrypted. This ensures that if attackers gain access to the files, they cannot use them without the decryption key. Other security features include role-based access controls to restrict access to the data. 
• Visibility—the service console enables users to know what is being applied to the VM as well as who is managing them. 

Cons

• Price—one of the biggest drawbacks of vSphere is the cost of the added benefits and license upcharges. 
• Complexity—the web console interface features a large number of configuration options, which can overwhelm inexperienced administrators. 
• Lack of error visibility—when an error occurs, the system often returns an “Unknown error” message, without describing the actual flaw. Luckily, users can turn to VM forums to find out the source of the mistake, but it could be better if the software provides more details about errors. 

Kubernetes vs vSphere: Alternative or Integration?

Although VMware and Kubernetes are virtualization technologies, the optimal use cases can be different. Containerization offers a faster way to deploy software while VM enables hardware-level isolation. However, it is possible to integrate both technologies to have the benefits of security and isolation while maintaining the portability of the containers.