ESXi, pronounced E-S-X-I, stands for Elastic Sky X Integrated. It is a bare-metal hypervisor developed by VMware for deploying and serving virtual machines.
What is a Hypervisor?
A hypervisor, also known as virtual machine monitor (VMM), is a software that creates and runs virtual machines (VMs). It allows multiple VMs with different operating systems to run on a single physical machine.
The hypervisor manages and allocates computing resources from the host machine to the virtual machines. This allows multiple operating systems and applications to run in isolated environments.
Key Benefits of ESXi
- Efficient resource utilization – ESXi enables efficient allocation of host resources like CPU, memory, storage and network to VMs based on requirement. This leads to better hardware utilization.
- Scalability – It is designed to be highly scalable to host large number of VMs by utilizing clustering and resource sharing capabilities.
- Reliability – The isolated VMs provide reliable fault and crash protection. If one VM fails, it does not affect other running VMs.
- Security – VM isolation also provides strong separation between VMs strengthening security. Restricted direct access to host hardware also adds a layer of security.
Working of ESXi
ESXi installs directly on the host server hardware allowing consolidation and sharing of resources for efficiency.
It provides a console user interface and application programming interfaces (API) to create, configure, manage and monitor virtual machines and resources.
The key components involved are:
- ESXi Host – The physical server that runs the hypervisor.
- VMs – These are virtual machines that utilize resources abstracted from the underlying host.
- vSphere – This is the management infrastructure for handling pools of resources and hooks them to virtual data centers.
- vCenter Server – This enables centralized management of multiple ESXi hosts and VMs across distributed infrastructure.
Advantages of ESXi Over Other Hypervisors
ESXi has a compact disk footprint of less than 150MB as it has no clients or agents. This frees up resources for VMs.
The smaller attack footprint limits vulnerabilities. VM isolation limits security breaches.
Direct Hardware Access
This allows improved performance for VMs instead of going through an intervening software layer.
Direct hardware integration provides reliable fault tolerance. The Service Console provides rescue, recovery and remote management.
Distributed Resource Scheduling dynamically allocates and balances computing capacity ensuring high scalability.
ESXi is VMware’s lean, purpose-built bare-metal hypervisor installed directly on server hardware providing efficient utilization that is secure and scalable. With capabilities like VM isolation, reliability and resource management it is widely used in data centers.
ESXi stands for Elastic Sky X Integrated and is a hypervisor developed by VMware for deploying virtual machines. It provides efficient resource utilization, security, scalability and reliability.
- ESXi stands for Elastic Sky X Integrated and is a bare-metal hypervisor by VMware.
- It enables running multiple VMs efficiently utilizing underlying server hardware resources.
- Key benefits include scalability, security, fault tolerance and direct hardware access performance.
- ESXi has a smaller attack surface and is more secure than hosted hypervisors.
- Distributed Resource Scheduling provides dynamic resource balancing for scaling load.
Frequently Asked Questions
Q: What type of hypervisor is ESXi?
A: ESXi is a bare-metal (Type 1) hypervisor running directly on the host server.
Q: How is ESXi licensed?
A: ESXi has both free and paid licensed versions with varying capabilities.
Q: Can ESXi be installed on Linux?
A: No, ESXi installation requires certified server hardware and is not supported on Linux.
Q: Is VMware vSphere the same as ESXi?
A: No, vSphere is the cloud computing virtualization platform that manages pools of computing resources while ESXi is the bare-metal hypervisor that serves as the foundation.
Q: What are the hardware requirements for installing ESXi?
A: 64-bit x86 server hardware with Intel VT or AMD-V hardware virtualization support enabled in BIOS is required.
Q: Can you convert a physical Windows server to an ESXi host?
A: Yes, you can install ESXi on a physical server replacing Windows server turning the hardware into an ESXi host.
Q: Is guest OS modification required for ESXi?
A: No, guest VMs can run unmodified OSes without installation of VMware tools providing hardware virtualization support.
Q: Which storage protocols are supported by ESXi?
A: ESXi supports Fibre Channel, FCoE, NFS 4.1, iSCSI, RDM for direct SAN access by VMs.
Q: What are the typical use cases for using ESXi hypervisor?
A: Server consolidation, Infrastructure-as-a-Service (IaaS), Virtual Desktop Infrastructure (VDI) and disaster recovery environments.
Q: What programming and scripting options does ESXi offer?
A: PowerCLI provides CLI access while ESXi offers Python and Perl options for scripted automation and management.
Q: Can you implement fault tolerance on ESXi free version?
A: No, vSphere fault tolerance capability is only included in licensed paid versions to protect critical workloads.
Q: Does ESXi offer dynamic resource optimization?
A: Yes, Distributed Resource Scheduler (DRS) enables automatic real-time optimization and load balancing across hosts.
Q: What is vMotion in relation to ESXi?
A: It is VMware’s live migration technology for moving running VMs across ESXi hosts without service interruption.
Q: What version release of ESXi is the latest?
A: Currently it is ESXi 8.0 with support for security tools like VM encryption and DirectX 12 GPU virtualization.
Q: How is ESXi patched and upgraded?
A: It has to be done through the VMware vCenter Server using baselines for seamless patching including VMware Tools upgrades.