Learn What a VMware Host Is and How to Manage It

A host virtual machine (VM) and guest VM are two crucial components of any virtualization platform. While a host VM provides the underlying hardware resources like processing power, memory, networking, and storage during virtualization, a guest VM is the software component of the VM, comprising an operating system (OS) and associated applications. VMware ESXi—a type 1 hypervisor developed by VMware—is the VMware host for VMs. VMware ESXi runs directly on the hardware as a bare-metal hypervisor, effectively partitioning it to consolidate applications. Discover the features and specifics of the VMware host in this post.

VMware’s hypervisor comes in two flavors: ESX and ESXi. Both run directly on the bare machine, have their own kernel, and are primary components of the VMware vSphere environment. However, ESXi offers superior architecture compared to ESX, which VMware has since deprecated.

Learn about VMware Host for Virtual Machines

VMware replaced the service console (an elementary OS) in ESX with a more integrated OS in ESXi to provide robust security, reliability, and management for the hypervisor. VMware ESXi runs its own kernel (also called VMkernel) that allocates memory, schedules the processor, and provides other hardware abstraction and OS services.

Below are some core features of VMware host:

Ultra-thin architecture. VMware ESXi has a small footprint with minimal interfaces—it doesn’t rely on the general-purpose OS. This minimizes its overall attack surface and reliability.
An integrated model based on application programming interfaces (APIs). The API-based model helps IT administrators to automate many routine tasks using command-line scripting tools like vSphere command-line interface (vCLI) and VMware PowerCLI.
Memory overcommitment. By allowing VMs to use more memory than what is available in the physical host, VMware ESXi provides higher consolidation ratios.
High scalability. VMware ESXi has massive scalability options, allowing as high as 768 logical processor cores, 512 virtual CPUs (vCPUs) and up to 1024 VMs per host.
Easier patching options. Because VMware ESXi is more compact and has minimal components, it is easier to patch. This helps to shorten service windows while enhancing its overall security.
Single sign-on (SSO). You can access vCenter Server instances on multiple devices without further authentication after logging in once.
Inventory search. You can access hosts, VMs, networks and storage devices via a single click.
Extensibility and scalability. You can run up to 2,000 hosts and 35,000 VMs on a single vCenter Server instance.
Audit trails. vCenter Server keeps track of records regarding essential changes to ESXi hosts and VMs. You can use these audit trails to enforce security within the VMware vSphere environment.
Multi-hypervisor management. vCenter Server can integrate VMware ESXi and other third-party hypervisors such as Microsoft Hyper-V. IT administrators can use this feature to manage multiple hypervisor environments.
Host profiles management. vCenter Server captures the configuration details about the host, including storage, networking, and security settings that you can deploy to other hosts.
Alerts and notifications. vCenter Server has inbuilt triggers that can start workflows automatically. You can use these triggers to minimize the time it takes to solve emerging problems.

Move Virtual Machines between VMware Hosts

Moving VMs from one location to another, and across VMware hosts and storage locations (even datacenters), is one of the significant advantages of vCenter Server. It allows users to:

Enhance performance. If one ESXi host is busy, you can migrate VMs from that host to another without any downtime.

Perform hardware maintenance. IT administrators can take down physical servers for planned maintenance by moving the VMs to other hosts. This allows mission-critical applications to stay online during the maintenance period.
Achieve HA. vCenter Server can proactively restart VMs on other servers if the current host crashes to ensure services don’t get interrupted. This can extend to an entire data center with all its ESXi hosts and VMs, which can restart on servers in a different data center.
Replace physical servers. You can replace a physical server with a new model by migrating its VMs to a new host with no downtime. Afterward, you decommission the old server.

VMware vMotion—vCenter Server’s feature—takes live VMS and migrates them from one ESXi host to another. vMotion ensures a seamless migration because the VM retains its network identity and connections. Therefore, you can only use vMotion to change between physical servers and not the storage locations.

In this regard, both the source and destination vCenter Server instances should connect to a shared VM storage. Additionally, the source and destination vCenter Server version instances on the physical servers should be 6.0 or later.

Load Balance across VMware Hosts

VMware uses a license feature called Distributed Resource Scheduler (DRS) to provide scheduling and load balancing capabilities at the virtualization layer. With VMware DRS, IT administrators define rules that specify how physical resources are allocated among the VMs. IT administrators can also add, remove or reorganize resource pools when necessary.

When enabled, DRS balances the memory load on all VMs within a VMware cluster. It redistributes the physical resources to VMs and ESXi hosts intelligently, depending on the workload requirements. For example, if the overall workload decreases, DRS can shut down some ESXi hosts temporarily to consolidate resources.

On the other hand, when workload demands rise, DRS assesses its priority against resource allocation rules and redistributes the VMs to ensure their capacities get dedicated to mission-critical applications.

Manage VDI Using a Single Pane of Glass with Parallels RAS

Consistently meeting business-critical applications is a top priority for organizations that want to compete in today’s fast-paced digital environment. Server virtualization can allow organizations to achieve maximum use of their physical servers by increasing the mobility of their applications.

However, server virtualization alone cannot address many issues bedeviling enterprise computing in the wake of the increased consumerization of IT and emerging working models. Parallels® Remote Application Server (RAS) is a better solution for organizations that want to deliver mission-critical applications under these scenarios. As a cloud-ready, out-of-the-box virtual desktop infrastructure (VDI) solution, Parallels RAS supports flexible working models such as remote working, hybrid working and part-time work from home. Organizations can streamline VDI management by using various Parallels RAS features such as:

Centralized IT management. IT administrators can undertake various tasks, including publishing corporate resources, monitoring resources, and managing connected devices via a single console.
Enhanced user experience (UX) and session management capabilities. Parallels RAS UX evaluator feature measures user experiences by calculating users’ elapsed time with published resources. IT administrators can also monitor user sessions proactively to determine which users require assistance.
Multi-tenancy capability. IT administrators have access to a consolidated solution for running multiple customer site deployments.
Granular access policies. IT administrators can restrict access to confidential resources via granular filtering rules based on users, groups, internet protocol (IP) addresses and incoming gateways.

Download the Parallels RAS trial today, and start to experience its VDI capabilities!