Definition of hypervisor and virtualization
To proceed, we need to understand some terminology. For us, 3 concepts are important: virtualization, hypervisor and platform for virtualization (they are the virtualization system).
So, virtualization is the technology of creating virtual (i.e. software) versions of servers/computers/workstations, usually called virtual machines (VM). The idea is simple - one real physical server runs several VMs isolated from each other, with their resources and operating systems running as independent systems. Virtualization makes it possible to use server or cluster resources more efficiently (more on clusters later), manage IT infrastructure, scale it, and reduce direct and indirect costs (if everything is done correctly). By the way, you can virtualize not only servers, but also networks, data stores, and even applications.
A hypervisor is an application software (software) that implements virtualization in practice. It creates and runs VMs, as well as manages them. A hypervisor enables a single server (host computer/host) to run multiple guest operating systems (OS) at the same time. It also divides the host's physical resources between VMs: memory, cores/threads, network, storage, etc. Such an internal combustion engine, without which all systems in the car will not work.
And finally, a platform for virtualization. If the hypervisor is the engine, then the virtualization platform is the car. Such platforms are not just a separate application, but a whole set of tools for creating and configuring virtual environments, managing resources and monitoring their work. Virtualization platforms can contain hypervisors of various types (usually 1 hypervisor per 1 platform, but there are more), management interfaces, resource managers, monitoring tools, backup systems, resource migration mechanisms, and much more.
The hypervisor can be used separately, or as part of the platform. The first is suitable for small infrastructures, personal use, testing and development, and the second option will be needed for complex projects.
Types of hypervisors
There are two main types of hypervisors:
1st type (Type 1) - aka "Bare-Metal", performed on "bare iron". This type of hypervisor operates at the hardware level, without the host operating system. In fact, this is a minimal OS. Examples include VMware ESXi, Microsoft Hyper-V (as well as Hyper-V Server), and KVM.
2nd type (Type 2) - aka "Hosted", host. These hypervisors run on top of the host operating system. They run as applications inside the operating system. Examples include VMware Workstation, Oracle VirtualBox, and Microsoft Virtual PC.
Advantages of hypervisor
Modern IT infrastructures are increasingly moving to virtualization. There are many reasons: optimization of resources and costs, improvement of management and fault tolerance. Hypervisors and virtualization systems are the basis of these processes, with many advantages for businesses, administrators and users.
- Speed: Hypervisors make it possible to create virtual machines almost instantly, unlike classic deployment on a hardware server. This makes it easy to provision resources to users as needed for dynamic workloads.
- Efficiency: Virtualization makes it possible to better reveal the potential of a server (or a cluster of servers). When multiple small tasks are performed on physical hardware instead of one large one, the chance of downtime is reduced. If in the classic version you have to use several underloaded servers for different server roles, then with a hypervisor you can use one more powerful, but fully loaded (usually they strive for 80%, and leave 20% as a reserve). This approach is more economical and energy efficient.
- Clustering: Hypervisors make it possible to create clusters from several physical servers, this guarantees fault tolerance (to some extent, depends on the parameters of the cluster and the number of its nodes aka nodes) and high availability of virtual machines. If one server in the cluster fails, the hypervisor automatically transfers the VM to other working nodes without stopping applications. This is called migration.
- Flexibility and Migration: Hypervisors typically support virtual machine migration features such as vMotion in VMware or Live Migration in Hyper-V. These functions allow you to move VMs between cluster hosts without stopping applications - you can service equipment or solve problems in parallel.
- Automatic crash recovery: Hypervisors typically support automatic crash recovery. If a VM or physical server becomes unresponsive, the hypervisor can automatically restart or move the VM to another server in the cluster.
- Backup and Replication: Some hypervisors and virtualization platforms come with built-in data backup systems and VMs, as well as replication mechanisms to remote servers, giving you additional layers of protection against failures and the ability to quickly restore data. PS Replication - creation and maintenance of an exact copy of data or VM in real time on another node or server. It is used for the fastest possible recovery.
Overview of popular hypervisors and comparative analysis.
VMware ESXi hypervisor
VMware ESXi is the most popular hypervisor of the 1st type (bare-metal) on the market. Functional, convenient and expensive. Especially interesting as part of the VMware vSphere virtualization platform. It is most often used in large-scale corporate IT infrastructures: hosting data centers, bank data centers, cloud providers, just large companies with their own infrastructure.
ESXi offers perhaps the widest set of features for virtualization and management of computing resources, storage and networks:
- Real-time migration (vMotion, vSphere Storage vMotion) and high availability vSphere HA (High Availability)
- Snapshots of the current state of the VM for further quick recovery if necessary.
- Dynamic allocation of host resources to allocate VM resources for current requirements.
- Convenient management and automation of tasks through the web interface.
- It is possible to integrate with VMware cloud services, such as VMware Cloud on AWS, to create hybrid clouds and migrate virtual machines between local and cloud environments.
ESXi also has a feature - a disadvantage for some (especially important for 7.0 and above): the list of compatible equipment (HCL). VMware guarantees work only on it, so before deployment, you need to check with the site. Otherwise, prepare for problems, up to non-working components. But this very feature guarantees an advantage - everything will work on approved components, and it becomes more difficult to shoot yourself in the foot.
However, ESXi provides excellent performance and scalability, making it ideal for managing a large number of virtual machines. Especially if you take into account convenient management through the vSphere Client web interface and API for automating tasks and integration with other systems.
All this has made VMware ESXi a kind of industry standard in corporate environments. But the price is more expensive than competitors, so it is not suitable for everyone. The closest competitor in terms of capabilities and market share is Microsoft Hyper-V.
Microsoft Hyper-V is also a common type 1 (bare-metal) hypervisor. Yes, I believe that it is of the 1st type :) Its main feature is that it is built from the beginning both in Windows Server and in the Windows client. You will be able to work with it through the graphical management interface and/or PowerShell right away, without additional installations. A great option if your infrastructure is built on the Microsoft stack and Windows-oriented applications. And ESXi is even cheaper, other things being equal.
In terms of functionality, everything here is also great:
- Quick VM creation, management, migration and monitoring.
- Full virtualization of resources, networks and storage, including SAN, NAS and cloud storage.
- Dynamic distribution - allows you to automatically distribute resources between VMs in real time, taking into account the current load.
- High availability Failover Clustering - will automatically recover VMs after host failures.
- Checkpoint - creation of VM snapshots, similar to snapshots in VMware ESXi. Allows you to save the current state of the virtual machine at a specific point in time.
- Creation of Hyper-V clusters for increased fault tolerance and effective resource management.
- Integration with Microsoft Azure cloud services to create hybrid clouds and migrate virtual machines between local and cloud environments.
ESXI and Hyper-V are paid solutions that are not affordable for everyone. We condemn piracy, and small businesses (although medium and large ones too) can use free software. One of the most popular open hypervisors is KVM (Kernel-based Virtual Machine).
Proxmox VE is also a type 1 (bare-metal) hypervisor built into the open source kernel of the Linux operating system and many distributions, which contributes to the spread. As you understand, it is free (GPL-license), but not at the expense of functionality and performance.
Proxmox is generally undemanding to host specifications, no strict iron requirements (forget HCL lists), can be run on a smart fridge if desired. Another question is how this connection will work.
Functionality in Proxmox VE is wide - both for simple tasks and for building large virtualized infrastructures:
- Proxmox VE allows you to create, start, stop and manage virtual machines based on KVM and LXC. KVM virtualizes hardware components, including CPU, memory, and peripherals, while LXC implements container virtualization, allowing you to run multiple isolated Linux containers on a single host.
- Proxmox VE can create multi-node clusters for fault tolerance and scalability. Clustering allows you to automatically balance the load and continue running applications if one of the nodes fails.
- Integrated tools for creating backup copies of virtual machines and restoring from them. This approach will protect you from data loss and allow you to quickly recover from failures and accidents.
- Monitoring - allows you to monitor the performance and use of resources of virtual environments, as well as keep logs of their work, create reports.
- Proxmox VE can be integrated with other management systems, such as OpenStack or Kubernetes, which expands functionality, management and automation capabilities.
Citrix Hypervisor is another popular virtualization platform built on the open-source Xen type 1 (bare-metal) hypervisor. The hypervisor itself is minimalist, free (GPL-license) and functional; implements a full-fledged virtualization environment for deploying virtual machines. Quite a competitor with other solutions from this article.
Key features of Citrix Hypervisor (Xen) :
- Xen hypervisor of the first type with high performance, reliability and security.
- Powerful tools for creating, managing and monitoring virtual machines, including logging and reporting. Support for many guest operating systems.
- Citrix Hypervisor can create clusters from several physical hosts to increase fault tolerance and infrastructure scalability + automatic load balancing.
- Easy integration with existing infrastructures.
- Maintenance without downtime due to the migration of virtual machines between nodes of the Citrix Hypervisor cluster.
- Integrated tools for backing up VMs and their automatic recovery, which provides increased data protection, as well as fast recovery after failures.
- Integration with other management systems, such as OpenStack or Kubernetes, which extends functionality and provides greater flexibility of management and automation.
Tips for choosing a hypervisor in 2024
First - everything depends on the requirements of your project and organization. That is, the approach is personal, and therefore the general advice from the article will not cover 100% of your questions. But still, it is useful to study them. If you have difficulties, you can write or call the managers of Server Solutions - the guys will tell you which equipment and hypervisor will fit your budget and tasks.
So, tips:
Analyze the requirements of your project. This is the first step. Assess scale, current or planned equipment, types of applications and nature of load.
Research: Explore hypervisors in more detail - our detailed blog articles are a good start, but you can dig even deeper, read the documentation, look at real cases and problems that others have faced to understand their features, advantages and disadvantages. I will provide a short comparison table, but additional research will not be superfluous.
- Consider compatibility and integration. Whichever hypervisor or platform you choose, it needs to be well integrated into the already existing IT infrastructure: SZD, monitoring, management, backup systems; check if your iron is listed in the HCL (may be critical for the same ESXi).
- Total cost of ownership and licensing. Open source is free, but may require more fine-tuning, more man-hours for administration, additional specialists and competencies in the technical team. You won't pay for the software itself, but the same Proxmox as a whole can be expensive (especially with paid support). So weigh all the pros and cons, maybe a paid hypervisor like Hyper-V is your option.
- Community. An active community of users will make your life easier. In general, all hypervisors from this article, except perhaps Xen, have a huge community. You will almost certainly find a solution to your problem or ask a question on the forums. But the Linux-KVM connection is in the leaders for this parameter. Other admins and experts will always share best practices, additional software, tools and training materials.
- Testing and evaluation. Test different hypervisors in your environment and evaluate their performance, reliability, and usability before going into battle. Many have basic versions, trials, etc.
Choosing a hypervisor or platform for virtualization is not easy. A comprehensive approach is required: competencies, a good understanding of IT infrastructures and business needs. If you need the help of professionals, we will tell you for free which equipment and software is right for you. We always select solutions for the budget and tasks.
Don't forget that deploying a virtualized infrastructure can both streamline processes and make them more difficult/expensive. A small business does not always need a hypervisor for simple office tasks, sometimes a couple of dedicated general-purpose servers are enough.
How can we help?
For more detailed information about the DELL PowerEdge R760 server with DDR5 4800 or the DELL PowerEdge R750 server with DDR4 3200, you can visit our website SERVER SOLUTIONS , to find out the price of the server, go to the DELL Server Configurator link .