Showing posts with label Virtualization. Show all posts
Showing posts with label Virtualization. Show all posts

Saturday, June 27, 2020

What is a snapshot in vmware ?

What is a snapshot in vmware ?


A snapshot preserves the state and data of a virtual machine at a specific point in time.

The state includes the virtual machine’s power state (for example, powered-on, powered-off, suspended).

-The data includes all of the files that make up the virtual machine.
-This includes disks, memory, and other devices, such as virtual network interface cards.

A virtual machine provides several operations for creating and managing snapshots and snapshot chains. These operations let you create snapshots, revert to any snapshot in the chain, and remove snapshots.

Sunday, June 14, 2020

VMware vSphere Components and Features

VMware vSphere Components and Features


The VMware vSphere includes the following components and features.

VMware ESXi:

A virtualization layer run on physical servers that abstracts processor, memory, storage, and resources into multiple virtual machines.


VMware vCenter Server:

The central point for configuring, provisioning, and managing virtualized IT environments. It provides essential datacenter services such as access control, performance monitoring, and alarm management.


VMware vSphere Client:

An interface that enables users to connect remotely to vCenter Server or ESXi from any Windows PC.


VMware vSphere Web Client:

A Web interface that enables users to connect remotely to vCenter Server from a variety of Web browsers and operating systems.


VMware vSphere SDKs:

Feature that provides standard interfaces for VMware and third-party solutions to access VMware vSphere.


vSphere Virtual Machine File System (VMFS):

A high performance cluster file system for ESXi virtual machines.


vSphere Virtual SMP:

Enables a single virtual machine to use multiple physical processors simultaneously.


vSphere vMotion:

Enables the migration of powered-on virtual machines from one physical server to another with zero down time, continuous service availability, and complete transaction integrity.

Migration with vMotion cannot be used to move virtual machines from one datacenter to another.


vSphere Storage vMotion:

Enables the migration of virtual machine files from one datastore to another without service interruption. You can place the virtual machine and all its disks in a single location, or select separate locations for the virtual machine configuration file and each virtual disk. The virtual machine remains on the same host during Storage vMotion.

Migration with Storage vMotion lets you move the virtual disks or configuration file of a virtual machine to a new datastore while the virtual machine is running. Migration with Storage vMotion enables you to move a virtual machine's storage without any interruption in the availability of the virtual machine.


vSphere High Availability (HA):

A feature that provides high availability for virtual machines. If a server fails, affected virtual machines are restarted on other available servers that have spare capacity.


vSphere Distributed Resource Scheduler (DRS):

Allocates and balances computing capacity dynamically across collections of hardware resources for virtual machines. This feature includes distributed power management (DPM) capabilities that enable a datacenter to significantly reduce its power consumption.


vSphere Storage DRS:

Allocates and balances storage capacity and I/O dynamically across collections of datastores. This feature includes management capabilities that minimize the risk of running out of space and the risk of I/O bottlenecks slowing the performance of virtual machines.


vSphere Fault Tolerance:

Provides continuous availability by protecting a virtual machine with a copy. When this feature is enabled for a virtual machine, a secondary copy of the original, or primary, virtual machine is created. All actions completed on the primary virtual machine are also applied to the secondary virtual machine. If the primary virtual machine becomes unavailable, the secondary machine becomes immediately active.


vSphere Distributed Switch (VDS):

A virtual switch that can span multiple ESXi hosts, enabling significant reduction of on-going network maintenance activities and increasing network capacity. This increased efficiency enables virtual machines to maintain consistent network configuration as they migrate across multiple hosts.


Host Profiles:

A feature that simplifies host configuration management through user-defined configuration policies. The host profile policies capture the blueprint of a known, validated host configuration and use this configuration to configure networking, storage, security, and other settings across multiple hosts. The host profile policies also monitor compliance to standard host configuration settings across the datacenter. Host profiles reduce the manual steps that are involved in configuring a host and can help maintain consistency and correctness across the datacenter.

Host profiles are also a component of vSphere Auto Deploy. The concept of an autodeployed host means that vCenter Server owns the entire host configuration and it is captured within a host profile. Certain policies require user input to provide host-specific values. To support Auto Deploy for host profiles, an answer file is created that contains the definitions for those policies.

Thursday, June 4, 2020

Different Types Of Disks In Vmware

Different Types Of Disks In Vmware


VMDK

Virtual disk is classified into 4 different categories:

-Alpha disk
-Delta disk
-Beta disk
-Gama disk

New VM with a disk:

Flat.vmdk (actual file)---ALPHA DISK
.vmdk (metadata file)

Snapshot disk:

Delta.vmdk (actual file)---DELTA DISK
.vmdk (metadata file)

Raw Device Mapping RDM-Physical

.rdmp.vmdk (actual file)---BETA DISK
.vmdk (metadata file)

Raw Device Mapping RDM-Virtual

.rdm.vmdk (actual file)---GAMA DISK
.vmdk (metadata file)

Vmware Startup Sequence

Vmware Startup Sequence






Vmware Important Configuration Files

Vmware Important Configuration Files



Wednesday, January 1, 2020

vCenter Cluster Setup

vCenter Cluster Setup


A cluster is a group of hosts. When a host is added to a cluster, the host's resources become part of the cluster's resources. The cluster manages the resources of all hosts within it.

Clusters enable the vSphere High Availability (HA) and vSphere Distributed Resource Scheduler (DRS) solutions. (We are going to discuss more HA and DRS in later part of the course).

We will be able to create a cluster under Datacenter.

To Create cluster >> Right click on data center and select ‘New Cluster’

VMware vCenter Server

VMware vCenter Server


vCenter server is a management tool, which allows us to manage multiple ESXi hosts and the Virtual machines.

We can connect vCenter with vSphere client same as we connect ESXi hosts, but the difference is:

‘When we connect to ESXi host with vSphere we can able to manage only that host’.

‘When we connect to vCenter server with vSphere we can manage multiple ESXi hosts.

In Simple, it is a centralized console to manage all our virtual infrastructure.

Apart from this we also get some advanced features like

-Cluster,
-HA (High Availability),
-DRS (Distributed resource scheduling),
-vMotion....and more. (Will discuss these in our next topics).

VMware vSphere suite Contains below products: -

-vCenter
-vSphere
-Web Client

Storage vMotion (SvMotion)

Storage vMotion (SvMotion)


SvMotion allows us to live migration of the virtual machine files (Configuration files, Disk files..Etc.) from one data store to another data store while virtual machine residing on the same host.

The difference between VMotion and SVMotion is that vMotion simply moves a VM from one ESX host to another, but keeps the storage location of the VM the same.

SvMotion changes the storage location of the VM while it is running and moves it to another data store on the same ESX host, but the VM remains on the same host.

Enhanced VMotion Compatibility (EVC)

Enhanced VMotion Compatibility (EVC)


Enhanced VMotion Compatibility (EVC) is designed to ensure the CPU compatibility between ESX hosts. EVC leverages the Intel FlexMigration technology as well as the AMD-V Extended Migration technology to present the same feature set as the baseline processors.

This means if we have different CPU on Hosts from same vendor/family (Intel/AMD) we can do migration by enabling EVC mode.

We can’t use the migration if we have CPU’s on hosts from different vendors.

WWN (World Wide Name)

WWN (World Wide Name)


A World Wide Name (WWN) or World Wide Identifier (WWID) is a unique identifier used in storage technologies including Fibre Channel, Advanced Technology Attachment (ATA) or Serial Attached SCSI (SAS).

WWN is a unique identifier that is assigned to a manufacturer by the Institute of Electrical and Electronic Engineers (IEEE) and hard-coded into a Fibre Channel (FC) device.

The names are usually 128 binary digits (bits) long but could be 64 bits if the device is older.

A WWN is similar in concept to a network card's media access control (MAC) address in an Internet protocol (IP) network but is formatted differently.

A bit more explanation needed…one example of usage should be good.

Types of Vmware Storage

Types of Vmware Storage


Storage Types:-
Below are the Storage types in simple definitions.

Local: - Stores files locally on an internal or external SCSI device.

Fibre Channel :- Stores files remotely on a Storage Area Network (SAN). Requires Fibre Channel adapters.

iSCSI (hardware initiated): -Stores files on remote iSCSI storage devices. Files are accessed over TCP/IP network using hardware-based iSCSI HBAs. It Uses CHAP authentication.

Network file system (NFS): - Stores files on remote file servers. Files are accessed over TCP/IP network using the NFS protocol. Requires a standard network adapter for network connectivity.

Vmware Data Store

Vmware Data Store


A data store is a manageable storage entity, usually used as a repository for virtual machine files including log files, scripts, configuration files, virtual disks, and so on.

vSphere supports two types of data stores, VMFS and NAS.

On Inventory go to Configuration >> Storage >> data stores
On the below screen we can see all the data stores assigned to selected ESXi host/Cluster.

Host Bus Adapter(HBA)

Host Bus Adapter(HBA)


The Host Bus Adapter(HBA) is Circuit board on Physical Host which provides Input /Output processing and physical connectivity between a host system, or server, and a storage and/or network device.

ESXi Host will have minimum of four HBA’s
If we want, see the HBA’s of the ESXi host, Got to the host configuration >> Storage adapters

HBA’s on ESXi hosts will be recognized with name VMHBA, like in the above screen (vmhba1, vmhba2, vmhba4, vmhba5).


What is DVN, dvPort and dvPort group

What is DVN, dvPort and dvPort group?


DVN – vNetwork

Distributed Virtual Network, is the umbrella name under which the new network infrastructure components are grouped. The official name that customers will hear is vNetwork.

dvSwitch  (DVS or Distributed Virtual Switch - vNetwork Distributed Switch)

Abstraction of multiple hosts sharing the same configuration for vSwitches and port groups.

vSwitch  - vNetwork Standard Switch

The “standard” virtual switch that is available in ESX 3.x and 4.x without vNetwork

dvPort

Port in a dvSwitch that allows VMs, vnics, VMKernel or Service Console nics.
dvPort status is stored in VC Database, so it is persistent across hosts

dvPortgroup

A collection of DVPorts that share the same configuration.


vSphere Distributed Switch

vSphere Distributed Switch


Provides centralized management and monitoring of the network configuration of all the ESXi hosts that are associated with the dvswitch.
Distributed switch can be created and configured at vCenter server system level and all its settings are propagated to all the hosts that are associated with the switch.
Network configuration and management for all the hosts that associated with the switch can be performed centralized on the vCenter server system

vDS Terminology: -
DVN – vNetwork

Distributed Virtual Network, is the umbrella name under which the new network infrastructure components are grouped. The official name that customers will hear is vNetwork.
dvSwitch  (DVS or Distributed Virtual Switch - vNetwork Distributed Switch)

Abstraction of multiple hosts sharing the same configuration for vSwitches and port groups.
vSwitch  - vNetwork Standard Switch

The “standard” virtual switch that is available in ESX 3.x and 4.x without vNetwork
dvPort

Port in a dvSwitch that allows VMs, vnics, VMKernel or Service Console nics.
dvPort status is stored in VC Database, so it is persistent across hosts
dvPortgroup

Collection of DVPorts that share the same configuration.

Virtual Machine Tools

Virtual Machine Tools


Virtual machine tools will have the drivers and utilities which improve the performance and connectivity between the Host and Virtual machine.

For Example,

Virtual machine tools are same like Motherboard drivers which you install on your desktop after the operating system installation.

These tools are installed on the Virtual machine once we install the operating system.

Vmware Snapshot Manager

Vmware Snapshot Manager


Snapshots

A snapshot preserves the state and data of a virtual machine at a specific point in time.In Simple terms, it’s like a Restore Point in windows where we can restore the operating system to the previous date. The state includes the virtual machine’s power state (for example, powered-on, powered-off, suspended).

The data includes all of the files that make up the virtual machine. This includes disks, memory, and other devices, such as virtual network interface cards.


Convert P2V using the Vmware Converter

Convert P2V using the Vmware Converter


P2V and V2V

Companies are focusing on Consolidating their data centers, means they are converting their physical infrastructure to the virtual infrastructure. As a part of Datacenter consolidation, they want to move their existing physical machines to the virtual environment without building a new machine.

With P2v (Physical to Virtual) method, we can migrate the physical machine to virtual machine. To do this we have different ways, one way is “VMware vCenter Converter Standalone” tool.

We will take a scenario like a client wants to migrate one critical Server which is running on the physical server to the virtual environment.

We can create a new Virtual machine on vCenter and install OS and applications on it but in this scenario, this physical server has some legacy application which we can’t install on a new machine, so we need to migrate the Physical machine with Converter tool.

Every Migration Process will have some Pre-Migration and Post-Migration steps which we need to follow in order to get a healthy virtual machine.

Resource Pool in Vmware

Resource Pool in Vmware


Resource pools are the Logical abstraction of Resources like RAM and CPU. To understand it in simple terms,

Assume that we have a group of critical virtual machines and we want all the required resources like RAM and CPU should always be available without any issue.

We can create the resource pools for the production, Development and test servers, and can assign the cluster resources according to the priority of the virtual machines