Setting up Disaster Recovery and quick recover business back
Now, let us understand virtualization concepts. Without knowing about it, makes anyone difficult to understand the cloud and container technologies.
What is Virtualization?
Technology that allows the creation of virtual versions of hardware, operating systems, storage, or network resources.
What is Virtual Machine?
Virtual machines (VMs) include an operating system, shared libraries, applications, and data essentially everything a physical server would have packaged inside them. As a result, VMs are relatively large in size and can be slower to start up compared to containers, which are much faster. Additionally, because VMs include their own operating systems and applications, they require more frequent updates and patches than containers.
What is Container?
A lightweight virtualization technology that packages applications with their dependencies, sharing the host OS kernel (e.g., Docker, Kubernetes).
Virtualization Forms
Server Virtualization:
Allocate a single physical server into multiple virtual servers, each running its own operating system and applications independently. Example: VMware ESXi, Microsoft Hyper-V.
Storage Virtualization:
Combines multiple physical storage devices into a single, unified virtual storage pool for easier management and scalability. Example: VMware vSAN, Dell EMC VPLEX, Netapp Storage.
Network Virtualization:
Abstracts physical network resources (switches, routers) to create virtual networks that can be managed and configured independently. Example: VMware NSX, Cisco ACI.
Virtualization Types:
Virtualization can be achieved at different hardware and software layers
Hardware Level
Software Level
1. Hardware-Level Virtualization
Operate at hardware layer. Create multiple Virtual machines on a Single/Pool of Physical Machines.
Types of Hardware-Level Virtualization:
I. Full Virtualization:
Simulates the entire hardware environment.
The guest OS runs unmodified as if it were on a physical machine.
Example: VMware ESXi, Microsoft Hyper-V.
II. Para Virtualization:
The guest OS is modified to communicate directly with the hypervisor for better performance.
It doesn’t fully simulate hardware, reducing overhead.
Example: Xen.
2. Software-Level Virtualization
Software virtualization creates virtual machines on top of an existing operating system.
What is Hypervisor?
Virtual Machines are created with the help of specialized virtualization software, called hypervisor, installed on a host machine. The hypervisor software has capable of creating multiple isolated virtual operating environments.
Hypervisors are classified into two types.
Type-1 hypervisor (native or bare-metal) runs directly on top physical host machine’s hardware, without the need an OS. Typically, they are found in enterprise.
Type-1 Hypervisors:
Amazon Web Services Nitro
IBM z/VM
Microsoft Hyper-V
Nutanix Acropolis Hypervisor (AHV)
Oracle SPARC/x86
Red Hat Virtualization (RHV)
VMware ESXi
Xen Hypervisor
KVM (Kernel-based Virtual Machine)
2. Type-2 hypervisor (hosted) operates on top of the host OS running on the hardware. Typically designed for end users, they can also be found in enterprise settings.
Type-2 Hypervisors:
VMware Workstation
VMware Fusion
Oracle VM VirtualBox
Microsoft Virtual PC
Parallels Desktop
QEMU
Red Hat Virtualization (Desktop variant)
Citrix XenServer (with host OS dependency in some cases)
Virtualization powers the infrastructure of the cloud and enhances containerization by providing isolation, scalability, and flexibility, making both technologies integral to modern IT environments.
How virtualization powers the cloud and container?
Virtualization Vs Cloud
Cloud Technology:
Virtualization forms the foundation of cloud computing by enabling efficient use of physical hardware. Here’s how it is used:
Resource Pooling: Virtualization allows multiple virtual machines (VMs) to run on a single physical server, optimizing resource utilization in cloud environments.
Scalability: Virtual machines can be created, cloned, or destroyed dynamically based on demand, enabling elastic scaling in public and private clouds.
Multi-Tenancy: Cloud providers use virtualization to isolate customer environments securely on shared physical infrastructure.
Platform Independence: Virtualization enables applications to run in VMs regardless of the underlying hardware or operating system, improving portability.
Disaster Recovery: Snapshots and live migrations make it easier to back up and recover cloud resources efficiently.
Hybrid Cloud Integration: Virtualization bridges on-premises data centers with public clouds, enabling hybrid cloud architectures.
Virtualization Vs Container
Container Technology:
While containers themselves are not full-fledged virtual machines, they rely on certain aspects of virtualization:
Operating System Virtualization: Containers use a shared OS kernel to isolate applications, reducing overhead compared to VMs. Technologies like Linux namespaces and cgroups enable this lightweight form of virtualization.
Lightweight Deployment: Containers virtualize only the application and its dependencies, allowing faster startup and smaller resource requirements than VMs.
Scalability in Microservices: Containers allow applications to be broken into microservices, with each service running in its container, enabling rapid scaling and updates.
Container Orchestration: Platforms like Kubernetes manage containerized workloads, leveraging virtualization for scheduling, resource allocation, and high availability.
Nested Use: Containers can run inside virtual machines to combine the flexibility of containers with the security and isolation of VMs.
Key Differences in Virtualization Usage:
Cloud: Focuses on virtual machines for creating isolated environments for customers or tenants.
Containers: Focuses on lightweight virtualization for packaging and running applications efficiently, often within cloud environments.
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