What is VMware vSphere?
VMware vSphere is not a specific product or software. VMware vSphere is the business name of the VMware suite. The VMware vSphere stack consists of virtualization, management and interface layers. The two core components of VMware vSphere are ESXi Server and vCenter Server. ESXi is hyperVSIor, where you can create and run VMS and virtual devices. VCenter Server is used to manage multiple ESXi hosts and pool host resources connected to the network. I hope this simple message clears your mind from the question “What is VMware vSphere?” Compared to other virtual machine management programs such as Microsoft Hyper-V and Citrix Xen Server, VMware vSphere is the master of the virtualization industry.
VMware vSphere history?
Before VMware vSphere, the entire VMware product suite was called “VMware Infrastructure.” With the release of VMware vSphere 4, VMware has renamed the name of its flagship product “VMware Infrastructure” to “VMware vSphere”.
VMware first released VMware Workstation, its root product, in 1998. VMware Workstation followed, releasing ESX (Elastic Sky X) and GSX (Ground Storm X) virtual machine management programs. ESX runs directly on server hardware (bare-metal HYPERVISOR), whereas GSX requires a host operating system. VMware GSX has been disabled, but the ESX family has been renamed ESXi, and there are many architectural differences and improvements in each ESXi host version.
Below is a brief product release history of VMware vSphere products, showing the evolution of VMware workstations to VMware vSphere 6.5.
What is VMware ESXi?
VMware ESXi is a bare-metal VM management program of VMware. VMware ESXi is ISO software that can be installed on physical hardware, such as Windows or Linux. ESXi installation occupies a small space of 144 MB. You can even install ESXi on a USB Pendrive. VMWare ESXi allows you to create multiple virtual machines to run multiple operating systems, such as Windows, Linux, Solaris, and macOS, on a single physical hardware. It gives you the ability to run workloads on top of virtual machines so that you can consolidate multiple physical hardware to run workloads on fewer physical hardware.
Before vSphere 5, vSphere had two VIRTUAL machine management programs, ESX and ESXi. With vSphere 5.0, ESXi is the only virtual machine manager.
VMware ESXi comes with both free and paid versions. As you might guess, the free version has almost no restrictions compared to paid ESXi. You cannot use vCenter Server to manage free ESXi VM monitoring programs. While free ESxi has few restrictions, it is enough to be evaluated before upgrading to advanced versions of ESxi for laboratory purposes, POC, and even for testing and development purposes.
What is VMware vCenter Server?
VMware vCenter is software that helps you centrally manage the entire VMware virtualization infrastructure. VCenter can add thousands of ESXi hosts to a list and manage multiple ESXi hosts and VMS running on them. VCenter Server provides many vSphere functions, such as VMware DRS, VMware HIGH Availability (HA), VMware vMotion, VMware fault tolerance, VM templates, and VM cloning.
VMware vCenter can be installed on a Windows or Linux-based vCenter (called vCenter Server Appliance). Recently switched from SUSE to Photon OS (VMware’s operating system) on vSphere 6.5. Understand the differences between Windows-based vCenter Server and vCenter Server devices. You must have an external database (such as Microsoft SQL Server or Oracle) or an embedded database (such as PostgreSQL) to install vCenter Server. PostgreSQL went from vSphere 6.0 to an embedded database before Microsoft SQL Server Express was an embedded database for VMware vCenter Server. The vCenter Server database stores information about virtual infrastructure list objects, such as ESXi host information, VM information, and performance data.
What are vSphere Client and vSphere Web Client?
I hope you are familiar with the basic concepts of VMware vSphere, VMware ESXi and VMware vCenter Server. Let’s learn what vSphere Client and vSphere Web Client are. The vSphere client and vSphere Web client are client software that help end users connect to the vCenter Server. Simply put, it is the same as an RDP client that helps you connect to a Windows server remotely. Similarly, vCenter Server is software that runs on Windows, and even Photo OS-based devices run only as services. We need vSphere Client or vSphere Web Client to connect to vCenter Server and manage the virtual infrastructure.
VSphere Client is a Client software that needs to be installed on a user’s desktop or laptop, but vSphere Web Client is a browser-based Client. You can use vSphere Web Client to manage vCenter Server without installing Client software. You can use vSphere Client to manage ESXi hosts, but vSphere Web Client can only manage vCenter servers. You can also manage ESXi 6.5 hosts using a Web browser using a host client. VSphere 6.5 will no longer provide vSphere Client (based on Windows).