Hypervisor
- Provides VMs with their virtual hardware
- Provides appropriate share of physical resources (CPU, HDD, RAM, Bandwidth) as defined.
- Performance is determined by the resources allocated to the VM.
Type 1: “Bare Metal” Hypervisors
Typically used for Data Center Virtualization due to less dependence on an OS and is more efficient because performs both rolls as single piece of software.
- Install as the Operating System
- No underlying OS required.
- Perform the functions of the Hypervisor (Resource manage features)
- Example: VMware ESXi
Type 2: “Hosted” Hypervisors
- Operate as an application on top of a pre-installed OS.
- Good if underlying hardware isn’t supported by Type 1 Hypervisor.
- Example: VMware Workstation
ESXi
- Bare Metal
- Performs roll of OS
- Direct access to hardware
- Can be installed onto Hard Drives, USB Flash Drives, SD cards
- Can also network boot from network tools such as PXE and TFTP Servers.
Common Tasks
- Create VMs
- Adjust VM Configurations
- Monitor Performance
- Configure and Patch Hosts
- To Manage all VMs in a single view, you need vCenter
vCenter
- Is an advanced manage suite that provides tools and features that make virtualization a natural extension of Data Center management.
- Capable of managing several VMs across several Hypervisors.
- Scalable – A single vCenter Instance can manage up to 1000 ESXi Hosts and 10,000 Powered On VMs. Additional instances can be installed as required.
- Idenity Management (Active Directory)
- Database Server
- Application Server
- Web Server
- VMware vSphere Web Client
- Can be installed on a Windows system or deployed as a virtual appliance.
- Able to install roles on one or multiple servers, depending on needs
- vCenter can be migrated into a Cloud Based configuration
What does vCenter Do?
- Provides ability to perform functions that require multiple ESXi hosts
- vMotion – Migrate running VMs from 1 ESXi host to another WITHOUT disrupting the VM!
- Distributed Resource Scheduler (DRS) – Load balancing for VMs across ESXi hosts. DRS leverages vMotion to balance these hosts.
- Distributed Power Management (DPM) – Power off unused ESXI hosts. Can also power them back on when needed!
- Storage vMotion – Migrates running VMs hard disks from one storage device to another
- Storage DRS – Automates Load Balancing from a Storage perspective
- vSphere Data Protection – Provides ability to backup VMs. Also provides
- High Availability (HA) – to restart VM on another host in case of Hardware failure
- Fault Tolerance (FT) – Provides uninterrupted availability for VMs
- vSphere Replication – Copy your VMs to another site for Disaster Recovery purposes