Knowledge Base

Virtualization technology is one of the cornerstones of today's modern computing infrastructure. Thanks to its advantages such as server consolidation, resource optimization, high availability, and disaster recovery, it allows businesses to reduce costs and increase operational efficiency. VMware ESXi is a prominent, industry-standard hypervisor in this field. In this comprehensive guide, we will examine in detail what ESXi is, how to install, configure, and manage it.

1. Introduction to ESXi: Basic Concepts and Advantages

1.1. What is a Hypervisor?

A hypervisor is a software that allows multiple virtual machines (VMs) to run on a physical server. By abstracting the hardware, it allows each VM to run its own operating system and applications independently. There are two basic types of hypervisors:

• Type 1 (Bare-Metal): Runs directly on the hardware. ESXi falls into this category. Provides higher performance and security.
• Type 2 (Hosted): Runs on an operating system (Windows, Linux, macOS). VMware Workstation and Oracle VirtualBox are examples. Offers easier installation and use, but performance is lower than Type 1.

1.2. Definition and Importance of ESXi

VMware ESXi is a Type 1 (bare-metal) hypervisor developed by VMware. It runs directly on the physical server hardware and enables the creation, management, and execution of virtual machines. ESXi forms the basis of the vSphere platform and provides a powerful and reliable solution for businesses to virtualize their server infrastructure.

1.3. Key Advantages of ESXi

• Server Consolidation: Reduces hardware costs by consolidating multiple physical servers into a single ESXi server.
• Resource Optimization: Optimizes resource utilization by dynamically sharing hardware resources (CPU, memory, storage) among virtual machines.
• High Availability: Increases business continuity by automatically moving virtual machines to another server in the event of a physical server failure, thanks to features such as VMware vSphere HA (High Availability).
• Centralized Management: Offers the ability to centrally manage ESXi servers and virtual machines with VMware vCenter Server.
• Easy Backup and Restore: Easy backup and restore of virtual machines simplifies disaster recovery processes.
• Advanced Security: ESXi has a security-oriented architecture and increases security by providing isolation of virtual machines.

2. ESXi Installation: Step-by-Step Guide

2.1. Hardware Requirements

Before installing ESXi, you need to ensure that your server meets the minimum hardware requirements. The most up-to-date requirements are available on VMware's official website, but generally, they are as follows:

• CPU: At least a 64-bit, x86 compatible processor
• Memory (RAM): At least 4 GB of RAM (8 GB or more recommended)
• Storage: At least 8 GB of disk space to install ESXi (SSD recommended)
• Network Adapter: At least one Gigabit Ethernet adapter
• BIOS/UEFI: The server's BIOS/UEFI must support and have enabled virtualization technologies (Intel VT-x or AMD-V).

2.2. Downloading the ESXi ISO File

To install ESXi, you must first download the ESXi ISO file from the VMware website. You may need to create a VMware account and obtain a free evaluation license.

2.3. Preparing the Installation Media

After downloading the ESXi ISO file, you need to create an installation medium. This can be a bootable USB drive or DVD. You can use tools like Rufus or Etcher to write the ISO file to the USB drive.

2.4. ESXi Installation

After preparing the installation medium, boot your server from this medium. The ESXi installation wizard will start. Follow the step-by-step instructions:

1. Accept the License Agreement: Read and accept the license agreement.
2. Select Your Installation Disk: Select the disk where ESXi will be installed. Note that the contents of the disk will be erased.
3. Select Your Keyboard Layout: Select your keyboard layout.
4. Set the Root Password: Set the root password that will be used to access the ESXi server. Make sure you choose a strong password.
5. Confirm the Installation: Review and confirm the installation settings.

After the installation is complete, the server will restart. Your ESXi server will now be up and running.

2.5. Post-Installation Configuration

After installation, you need to configure the ESXi server. You can connect to the ESXi Host Client using a web browser. To do this, enter the server's IP address in your browser (for example, https://192.168.1.100). Log in with the root username and password.

In the ESXi Host Client, you can make the following configurations:

• Network Settings: Configure the IP address, network mask, default gateway, and DNS servers.
• Storage: Create datastores. These datastores are used to store the disk images of virtual machines.
• Users and Groups: Create additional users and groups.
• Security: Configure security settings.

3. ESXi Configuration: Network and Storage

3.1. Network Configuration

The network configuration of an ESXi server is critical for virtual machines to access the network and communicate with other servers. ESXi manages the network connection of virtual machines using virtual switches (vSwitch).

3.1.1. Virtual Switches (vSwitch)

A vSwitch is a virtual equivalent of a physical switch. It allows virtual machines to communicate with each other and with the physical network. There are three types of vSwitch in ESXi:

• Standard vSwitch: Runs on a single ESXi server.
• Distributed vSwitch: Centrally managed across multiple ESXi servers (requires vCenter Server).
• Private vSwitch: Allows only virtual machines on the same ESXi server to communicate with each other. There is no access to the physical network.

3.1.2. Port Groups

Port groups are used to group ports on a vSwitch. Each port group can have a specific VLAN ID or security policy. Virtual machines access the network by connecting to a port group.

3.1.3. VMkernel Adapters

VMkernel adapters are used for the ESXi server itself to access the network. Separate VMkernel adapters can be created for different purposes such as management traffic, vMotion traffic, iSCSI traffic, and NFS traffic.

3.2. Storage Configuration

The storage configuration of an ESXi server is used to store disk images of virtual machines. ESXi supports different storage protocols:

• Local Storage: Disks directly connected to the ESXi server (SATA, SAS, SSD).
• iSCSI: Block-based storage over an IP network.
• NFS: File-based storage over an IP network.
• Fibre Channel: Block-based storage over a dedicated network.

3.2.1. Datastores

Datastores are logical units used to store disk images (VMDK files) and other files of virtual machines. ESXi supports different datastore types:

• VMFS: A file system specific to VMware. It is the most commonly used datastore type.
• NFS: A network directory shared using the NFS protocol.
• vSAN: VMware's software-defined storage solution.

3.2.2. LUNs and Targets (for iSCSI)

If you are using iSCSI, you need to configure LUNs (Logical Unit Number) and targets. A LUN represents a disk volume on an iSCSI storage device. The target is the IP address and port number of the iSCSI storage device.

4. Virtual Machine Creation and Management

4.1. Virtual Machine Creation

You can use the ESXi Host Client or vCenter Server to create a virtual machine on ESXi. The steps to create a virtual machine with the ESXi Host Client are as follows:

1. Log in to the ESXi Host Client.
2. Click on the "Virtual Machines" tab.
3. Click on the "Create / Register VM" button.
4. Select the "Create a new virtual machine" option and click "Next".
5. Give the virtual machine a name, select a compatibility option, and select an operating system family and version. Click "Next".
6. Select the datastore where the virtual machine will be stored. Click "Next".
7. Configure the CPU, memory, disk, and network settings to be assigned to the virtual machine. Click "Next".
8. Review the settings and click "Finish".

4.2. Virtual Machine Management

You can use the ESXi Host Client or vCenter Server to manage virtual machines. You can perform the following operations:

• Start, stop, restart, and suspend the virtual machine.
• Access the console of the virtual machine.
• Assign resources (CPU, memory, disk) to the virtual machine.
• Configure network settings for the virtual machine.
• Back up and restore the virtual machine.
• Clone the virtual machine and create a template.

4.3. Virtual Machine Performance Monitoring

Monitoring the performance of virtual machines is important to optimize resource utilization and detect problems. The ESXi Host Client and vCenter Server provide tools to monitor performance metrics such as CPU usage, memory usage, disk I/O, and network traffic of virtual machines.

5. ESXi Security: Best Practices

5.1. Use Strong Passwords

Use strong and unique passwords to access the ESXi server and virtual machines. Set complex passwords for the root password and other user accounts.

5.2. Enable the Firewall

Prevent unauthorized access to the server by enabling the ESXi firewall. Open only specific ports for necessary services.

5.3. Install Updates Regularly

VMware regularly releases security updates for ESXi. Close security vulnerabilities and protect your server by installing these updates regularly.

5.4. Configure Access Control

Grant access to the ESXi server and virtual machines only to authorized users. Use role-based access control (RBAC) to ensure that users can only access the resources they need.

5.5. Monitor Logs

Detect suspicious activity and prevent security breaches by regularly monitoring the logs of the ESXi server and virtual machines.

6. ESXi Management: vCenter Server

6.1. What is vCenter Server?

VMware vCenter Server is an application used to centrally manage multiple ESXi servers and virtual machines. vCenter Server offers the following advantages:

• Central Management: The ability to manage multiple ESXi servers from a single interface.
• High Availability: Automatic migration of virtual machines to another server with vSphere HA (High Availability).
• Resource Management: Automatic distribution of resources with vSphere DRS (Distributed Resource Scheduler).
• Advanced Monitoring and Reporting: Monitoring and reporting of performance metrics.
• Automation: Automating tasks with PowerCLI.

6.2. vCenter Server Installation

To install vCenter Server, you need to download the vCenter Server ISO file from VMware's website. By following the installation wizard, you can install vCenter Server on a Windows server or as a vCenter Server Appliance (vCSA).

6.3. vCenter Server Configuration

After installing vCenter Server, you need to add ESXi servers to vCenter Server. You can also organize your virtual machine infrastructure by creating objects such as data centers, clusters, and resource pools.

6.4. Management with vCenter Server

With vCenter Server, you can create, manage, monitor, and move virtual machines. You can also configure advanced features such as vSphere HA, vSphere DRS, and vSphere vMotion.

Tables

Table 1: Hypervisor Comparison

Table 2: ESXi Storage Protocols

Code Examples

Starting a Virtual Machine with PowerCLI

# Specify the virtual machine name
$VMName = "MyVM"

# Start the virtual machine
Start-VM -VM $VMName

Listing Network Interfaces with ESXi Shell

# Log in to ESXi Shell

# List network interfaces
esxcfg-nics -l

Key Points

• ESXi is a Type 1 (bare-metal) hypervisor.
• ESXi forms the basis of the vSphere platform.
• vCenter Server is used to centrally manage multiple ESXi servers.
• Security is of critical importance in ESXi management.
• Regular updates and firewall configuration are important.

Step-by-Step Instructions

Adding a Disk to a Virtual Machine with ESXi Host Client

1. Log in to the ESXi Host Client.
2. Click on the virtual machines tab and select the virtual machine you want to add a disk to.
3. Select "Edit Settings" from the "Actions" menu.
4. Select "Hard Disk" from the "Add new device" drop-down menu.
5. Configure the new disk's size, type, and storage location.
6. Click the "Save" button.

Real-Life Examples and Case Studies

Example 1: A retail company consolidated 10 physical servers into 2 ESXi servers using ESXi. This saved 80% on hardware costs and significantly reduced energy consumption.

Example 2: A financial institution ensured high availability of its critical applications using vSphere HA. When one server failed, virtual machines were automatically moved to another server, ensuring business continuity.

Visual Explanations

(Textual Description): A diagram showing that an ESXi server runs on hardware and virtual machines run independently on that hardware. Each virtual machine runs with its own operating system and applications. ESXi abstracts the hardware, allowing virtual machines to share hardware resources.

Frequently Asked Questions

Is ESXi free?

VMware offers a free version of ESXi. However, the free version has some limitations (for example, it cannot be managed with vCenter Server). For production environments, it is recommended to use a licensed version.

On what hardware can I use ESXi?

ESXi supports a wide range of server hardware. However, it is important to check VMware's hardware compatibility list (HCL). This list shows the hardware that is compatible with ESXi.

Can I manage ESXi without vCenter Server?

Yes, you can manage a single ESXi server using the ESXi Host Client. However, it is recommended to use vCenter Server to manage multiple ESXi servers.

Conclusion and Summary

VMware ESXi is a powerful and reliable solution in the field of virtualization. Thanks to its advantages such as server consolidation, resource optimization, high availability, and centralized management, it allows businesses to reduce costs and increase operational efficiency. In this guide, we have examined in detail what ESXi is, how to install, configure, and manage it. By using ESXi effectively, you can maximize the potential of your computing infrastructure.