Category: Virtualisation

Components of VMware vSphere 6.0 – part 6

This is another blog post to break into part the VCA Data center Virtualization training. So far articles already published are:

  1. An introduction of Data Center Virtualization
  2. Components of VMware vSphere 6.0 – part 1 which include an overview of Vsphere 6.0, its architecture, Topology and configuration maximums.
  3. Components of VMware vSphere 6.0 – part 2 which include an introduction to vCenter servers and its features.
  4. Components of VMware vSphere 6.0 – part 3 which include Shared Storage, Shared Protocols, Data Stores, Virtual SANs and Virtual Volumes
  5. Components of VMware vSphere 6.0 – part 4 which include Networking feature in vSphere, Virtual Networking, Virtual Switches, Virtual Switch types and Introduction to NSX
  6. Components of VMware vSphere 6.0 – part 5 which include vSphere Resource management features, vMotion, DRS, DPM, Storage vMotion, Storage DRS, Storage I/O control and Network I/O control.

This part will address with the following topics:

  • vSphere availability features
  • vSphere data protection
  • High Availability
  • Fault tolerance
  • vSphere replication

vSphere availability features

VMware vSphere delivers maximum availability of your virtualized environment making unplanned downtime of thing of the past. The enhanced availability also minimizes unplanned downtime through automated virtual machine restart. Automatic virtual machine placement and load balancing, Backup and Recovery and Site wide Disaster recovery enhances availability. The vSphere availability features include vSphere Data Protection, High Availability, Fault tolerance and vSphere replication.

vSphere Data Protection

VMware vSphere data protection is a robust easy to deploy disk-based backup and recovery solution for VMware virtualized environment. The feature enables both local data protection and off site disaster recovery. Backups are performed locally and then replicated offside for disaster recovery. Data Protection is managed using the vSphere web client, an interface that is familiar to the vSphere administrator. With data protection, tasks such as creating Backup jobs, Restoring virtual machines and Backup data replication are intuitive.

Photo Credits: VMware
Photo Credits: VMware

Data protection includes agents that enables application consistent backup and recovery from a wide variety of servers including the Microsoft SQL server, Microsoft Exchange server and Microsoft Sharepoint server. It allows you to restore the replicated backup data to a target location or back to the source location. This functionality provides several retention and recovery options to  satisfy a wide variety of business requirements. Data protections also include automates backup verification schedule jobs that routinely restore virtual machines, boot the guest operating systems and check for VMware tools heart beats to verify if the virtual machines have been recovered successfully and then delete the restored virtual machines. The data protection support for backup data storage provides increased reliability and backup data capacity with minimum impact on network bandwidth and performance.

High Availability

High Availability proposes easy to use, cost effective high availability for applications running on virtual machines. In the event of physical server failure affected virtual machines are automatically restarted on other server with space capacity. In a case of operating system failure, HA restart the affected virtual machine on the same physical server.

Photo credits: VMware.com
Photo credits: VMware.com

The combination of HA and the other availability features of the vSphere platform provides organisations with the ability to select and deliver the level of availability required for all their important applications. HA enables you to minimise unplanned downtime and IT service disruptions. While eliminating the need for dedicated standby hardware or the installation of additional software. It provides affordable and uniform HA across the entire virtualized IT environment without the cost and complexity of fail over solutions tie to either operating systems or specific applications. To monitor operating system failures, HA monitor heartbeat information provided by the VMware tools package installed on each virtual machine on the cluster. Failure are detected when no heart beat  received from a given virtual machine within a specified time interval.

Photo credits: VMware.com
Photo credits: VMware.com

Fault Tolerance

vSphere Fault Tolerance is an important feature that allows you to protect mission critical high performance applications regardless of the operating systems or other running applications. It provides continuous availability for applications in the event of physical server failures by creating a lock step of virtual machine that is always up to date with the primary virtual machine. In the event of hardware outage, Fault Tolerance automatically triggers fail over ensuring zero downtime and preventing data loss. vSphere Fault Tolerance is easy to set up and configure and does not require any other operating system and application specific agent and configurations. It is tightly integrated with vSphere and managed using the vSphere web client. Fault tolerance can support up to 4 vCPUs and 64 GB of memory thus providing protection for approximately 90% of mission critical customer workloads regardless of the application or operating system.

A traffic between hosts where primary and secondary virtual machines are running is referred as Fault Tolerance logging. In vSphere 6.0, Fault Tolerance logging is very bandwidth intensive and the use of a dedicated 10 GB of NIC on each host is recommended. Though this is not a requirement, without the necessary bandwidth, the protected virtual machine would be slower. vSphere 6.0 Fault Tolerance creates a copy of the entire virtual machine resulting in total protection for virtual machine storage, compute and memory. It also allows you to store primary and secondary VM files on both shared as well as on local storage. This result in increased protection, reduced risk and improved flexibility. You can use VMware snapshot based tools to backup the Fault Tolerance protected virtual machine enabling easier Backup Administration and Data Protectioin and Reduced Risks. Fault tolerance support all virtual disk types, including Eager-Zeroed Thick, Thick and Thin disks.

Photo credits: VMware.com
Photo credits: VMware.com

Host compatiblity for vSphere Fault Tolerance is now the same as for vSphere vMotion. These features make is easy to use Fault Tolerance.

vSphere Replication

vSphere Replication is a feature to provide data protection and disaster recovery for vSphere platform by replicating virtual machine within the same site of cross-site. It create a copy of the virtual machine that can be stored locally within a cluster or another site providing a data storage to rapidly restore the virtual machine within minute. This recovery process is simpler and faster as compared to the process of restoring from a backup. In vSphere 6.0, replication is tightly integrated with vSphere and is managed using vSphere web client. It allows you to create as many as 24 recovery points for a replicated VM. It also provides you with the option to minimize network bandwidth consumption by controlling the frequency and Extent of Replication. Further, the replicated data is compressed as it is sent across the network and stay compress until it is written to storage. Though compressing and decompressing them replicated data cost some CPU cycles on the source and target storage host, the result is always balanced between Performance, Compression and Limited overhead. vSphere 6.0 allows you to easily isolate network traffic associated  with vSphere replication from other vSphere host traffic. This allows you to control bandwidth by configuring more and more NIC in a vSphere replication virtual appliance and by using vSphere network I/O control to separate network traffic. At the source, administrators can specify a NIC for replication traffic and use Network I/O control to control replication bandwidth utilization. At the target vSphere replication appliances can have multiple NICs with separate IP addresses to separate incoming traffic isolated controllable flows. The administrator can specify one of the NICs for incoming replication traffic to be written to storage and the result is improved performance and security.


Components of VMware vSphere 6.0 – part 5

I made my best to break the VMware vSphere 6.0 tutorial into related parts so that it is more easy to grasp the important materials. So far articles already published are:

  1. An introduction of Data Center Virtualization 
  2. Components of VMware vSphere 6.0 – part 1 which include an overview of Vsphere 6.0, its architecture, Topology and configuration maximums.
  3. Components of VMware vSphere 6.0 – part 2 which include an introduction to vCenter servers and its features.
  4. Components of VMware vSphere 6.0 – part 3 which include Shared Storage, Shared Protocols, Data Stores, Virtual SANs and Virtual Volumes
  5. Components of VMware vSphere 6.0 – part 4 which include Networking feature in vSphere, Virtual Networking, Virtual Switches, Virtual Switch types and Introduction to NSX

In this article i will continue on with the following aspects:

  • vSphere Resource Management Features
  • vMotion
  • Distributed Resource Scheduler
  • Distributed Power Management
  • Storage vMotion
  • Storage DRS
  • Storage I/O control
  • Network I/O control

vSphere Resource Management Features

Resource Management is the allocation of resource from resource providers to resource consumers. Resource management allows you to dynamically re-allocate resources so that you can more efficiently use available capacity. The various features that allows to perform resource management include vMotion, DRS, DPM, Storage vMotion, Storage DRS, Storage I/O control and Network I/O control.

Photo credits: VMware.com
Photo credits: VMware.com

vMotion

vMotion allows you to migrate one virtual machine from one ESXi host to another without any downtime. You can also change both the host and the datastore of the virtual machine during vMotion. When you migrate virtual machine with vMotion, ensues to change only the host. The active memory and precise execution of the virtual machine is rapidly transferred to the new host. vMotion suspends the source of the virtual machine, copies the Bitmap to the new ESXi host and resumes the virtual machine on its new host. The associated virtual disk remains at the same location on storage that are shared between the two hosts. Only the RAM and the system state are copied to the new host.When you change both the host and the datastore, the active memory and VM execution state is copied to the new host and the virtual disk is move to another datastore.

vMotion migration to another host is possible in vSphere environments without shared storage. The different types of vMotion include:

Cross vSwitch vMotion

This allows you to seamlessly migrate a VM across different virtual switches while performing a vMotion.

Photo credits: VMware.com
Photo credits: VMware.com

Cross vCenter vMotion

This allows you to migrate VMs from a host server that is managed by one vCenter Server to a host managed by another vCenter Server

Photo credits: VMware.com
Photo credits: VMware.com

Long Distance vMotion

This allows you to migrate a WAN to another site. The latency across site is 150ms RTT (Round Trip Time)

DRS – Distributed Resource Scheduler

Aggregates computing capacity across a collection of servers into logical resource pools. It intelligently allocate available resources among the virtual machine based on predefined rules that reflect the business needs and changing priorities. Each DRS cluster has a root resource pool that group the resources of that cluster. The resource pools decide how VMs share memory resources. A resource pool allows you as an administrator to divide and allocate resources to virtual machines and other resource pools. A resource pool allows you to control the aggregate CPU and memory resources of DRS cluster.Resource pool also allows you to prioritize resources to highest value application in order to align resources to business goals automatically.

Photo credits: VMware.com
Photo credits: VMware.com

When a virtual machine experience an increase load or there is pressure or scarcity of available resources on its current host server, DRS may redistribute some virtual machines across some of the host servers to satisfy the resource needs of the consuming virtual machine. DRS offers several benefits:

  • It helps offers efficiency of the data center by automatically optimizing hardware utilization and respond to changing condition.
  • It also allows you to dedicate resources to business units whilst still profiting higher hardware utilization to resource pooling.
  • With DRS, you can conduct zero downtime server maintenance and lower power consumption cost by up to 20 %.

DPM – Distributed Power Management

DPM is a feature of VMware DRS that continuously monitors resource requirements in a DRS cluster. When resource requirements of the cluster decrease during periods of low usage, VMware DPM consolidates workload to reduce the power consumed by the cluster. When resource requirements of workloads increase during periods of high usage VMware DPM bring powered down hosts back on-line to ensure that service levels are met. DPM compare the available capacity in a DRS cluster against resource requirements of virtual machines plus some administrator defined buffer capacity requirements.

Photo credits: VMware
Photo credits: VMware

If DPM detects that there are too many hosts powered on, it will consolidates virtual machines onto fewer host and power off the remaining machines. VMware DPM bring powered off hosts online once again to meet virtual machines requirements either at a predefined time or when it senses increase in virtual machine requirements.

Storage vMotion

Storage vMotion enable you to migrate virtual machines and its disk files from one datastore to another while the virtual machine is running. It perform the virtual machine migration with zero downtime, continuous service availability and complete transaction integrity. With Storage vMotion, you can choose to place the virtual machine and all of its disks in a single location or select separate locations for the virtual machines configuration file and each virtual disk. Storage vMotion enables you to perform pro-active storage migrations, simplified array migrations and improve virtual machine storage performance. Storage vMotion is fully integrated with VMware vCenter server to provide easy migration and monitoring.

Storage DRS

Storage DRS provides smart virtual machine placement and load balancing mechanisms based on IO and space capacity. It helps decrease operational effort associated with the provisioning of virtual machines and monitoring of the storage environments. Storage DRS allows you to monitor the storage habits of the virtual machine and to keep the storage devices more evenly loaded. It is a load balancer just like DRS but focusses on storage devices. It monitors disk IO latency on a shared storage devices to determine if a particular device is overburdened. Storage DRS distributes the load in storage clusters to ensure smooth performance. It can be set up to work either on manual of fully automatic mode.

  • Manual mode – In the manual mode, Storage DRS makes balancing recommendations that an administrator may approve.
  • Automatic mode – In the automatic mode, Storage DRS makes storage vMotion decisions to lower I/O latency to keep all virtual machines performing optimally.

Storage I/O control (SIOC)

SIOC provides storage I/O performance isolation for virtual machines and enables administrators to comfortably run important workload in a highly consolidated virtualized storage environment. It protects all virtual machines from undoing negative performance impact due to misbehaving I/O heavy virtual machines. Note that SIOC can have negative performance if it is not set properly. SIOC protect the service level of critical virtual machine by giving them preferential I/O resource allocation during periods of congestion. It achieves this benefits by extending the constructs of shares and limits used extensively for CPU and Memory to manage the allocation of storage I/O resources. SIOC can trigger device latency that monitoring that hosts observe when communicating with datastore. When latency exceeds a set threshold, the feature engages to relieved congestion. Each virtual machine that accesses that datastore is then allocated I/O resources in proportion to their shares. SIOC enables administrators to mitigate the performance loss of critical workloads due to high congestion and storage latency during peak load periods. The use of SIOC will produce better and more predictable performance behaviour for workload during period of congestions.

Network I/O control (NIOC)

Administrators and architects need a simple and reliable way to enable prioritization of critical traffic over the physical network if and when contention of those physical resources occurs. NIOC addresses this challenge by introducing a software approach to partitioning physical network bandwidth among different types of network traffic flows. It does so by providing appropriate QOS policies enforcing traffic isolation, predictability and prioritization thereby helping IT organizations overcome the contention resulting from consolidation.  NIOC allows you to ensure a given flow will never be allow to dominate over others which prevents drops and undesire jitters. It also allows Flexible Network Partitioning to help users deal with overcommitment when flows compete aggressively for the same resources. NIOC enforces traffic bandwidth limit on the overall VDS set of dvUplinks and uses them efficiently for network capacity by load based teaming.


Components of VMware vSphere 6.0 – part 4

The fourth part of the Components of VMware vSphere 6.0 will consist of the following:

  • Networking Features in vSphere
  • Virtual Networking
  • Virtual Switches
  • Virtual Switch Types
  • Introduction to NSX

Articles already published are:

  1. An introduction of Data Center Virtualization 
  2. Components of VMware vSphere 6.0 – part 1 which include an overview of Vsphere 6.0, its architecture, Topology and configuration maximums.
  3. Components of VMware vSphere 6.0 – part 2 which include an introduction to vCenter servers and its features.
  4. Components of VMware vSphere 6.0 – part 3 which include Shared Storage, Shared Protocols, Data Stores, Virtual SANs and Virtual Volumes

Networking Features in vSphere

The networking features of vSphere provides support for Monitoring Networks, Managing Network Resources and Networking Best Practices. Network virtualization abstracts the network into a generalized pool of network capacity. The unified pool of Network Capacity can then be ultimately segmented into logical network directly attached to specific applications. The virtual machines communicate with each other and with the physical components to the virtual networks.

Photo Credits: VMware.com
Photo Credits: VMware.com

vSphere uses virtual NICs and virtual switches for virtual networking. Uplink adapters are physical NICs in each host that connect physical network to virtual network. Virtual switches regulate the traffic between the VMs.

Photo Credits: VMware.com
Photo Credits: VMware.com

vSphere uses NSX as the network virtualization platform for SDDC (Software Defined Data Center). NSX allows you to treat your physical network as a pool of transport capacity. With network and physical resources attached to virtual machines with a Policy-Driven approach.

Virtual Networking

Virtual machines use the virtual networking to communicate with each other and with the physical world. Virtual networking is similar to physical networking. Each virtual machine on the ESXi host has a network address, with zero or more virtual network cards. The virtual network cards are connected to virtual switches which allows virtual machine on the same host communicate with each other using the same protocol that would be used with physical switches. Virtual switches also allows virtual machine to communicate with VMs on other host. The ESXi hosts are managed by vCenter server and leverage the network with features such as vMotion, High Availability and DRS.

Photo Credits: VMware.com
Photo Credits: VMware.com

A virtual machine can be configured with zero or more virtual ethernet adapter, each of which has its own IP address and MAC address. As a result virtual machine has its own properties as virtual machines from a networking standpoint. vSphere supports a number of networking features including:

  • Virtual LANs – Provide logical separation of Network Traffic  and are used to isolate different sub-networks, such as a test or restore network
  • Traffic Shaping – Is a feature that allows you to regulate and/or restrict the inbound and outbound network bandwidth of a group of virtual machines. This feature helps to reduce the congestion in a virtual network.
  • Port Mirroring – Allows you to monitor a virtual machine’s traffic for troubleshooting or intrusion prevention. This feature allows you to capture the total traffic sent to or from a virtual machine for analysis.
  • QoS and DSCP – Quality of Service and Differentiated Services Code Point are networking standards that allow network switches to prioritise certain network traffic over others. Example is prioritise the voice traffic from a call manager server so that its performance is improved.
  • NetFlow – Is a network monitoring tool that determine the top talkers on a network. It also monitors other metadata about the communications that occur on the network.
  • CDP and LLDP – Cisco Discovery Protocol and Layer Discovery Protocol  are the discovery protocols that are used to identify the neighbouring physical switches. CDP and LLDP can also used to discover misconfigurations in network.

Virtual Switches

Virtual switches are the key networking components of vSphere virtual networking. You can use virtual Switches to attach virtual machines to the physical network. You can also use them to create isolated networks to be used during testing and development. Virtual switches help you to reduce network clutter by reducing the number of network cables plugged into your ESXi hosts. Virtual switches perform the following functions:

  • Look up each  frame’s destination MAC when it arrives.
  • Forward a frame to one or more ports for transmission.
  • Avoid unnecessary deliveries.

Virtual Switch Types

vSphere supports two main type of virtual switch i.e; Standard and Distributed switch.

Standard switch – can bridge traffic internally between virtual machines in the same port group and link to external networks. You can use standard switches to combine the bandwidth of multiple network adapters and balance communication traffic among them. You can also configure a standard switch to handle physical NIC failover. Standard switch models a physical Ethernet switch. The default number of logical ports for a standard switch is 120. Each uplink adapter associated with a standard switch uses one port.

Photo credits: VMware.com
Photo credits: VMware.com

Distributed switch – VMware vSphere distributed switch provide a centralized interface from which you can configure, monitor and administer virtual machine access switching for the entire data center. Distributed switch provides simplified virtual machine network configuration, and enhanced network monitoring and troubleshooting capabilities. The networking configuration and management for all hosts that are associated with the Distributed switch is centralized in the vCenter server system.

Photo credits: VMware.com
Photo credits: VMware.com

Introduction to NSX

NSX handle data across virtual switches without interacting  with the physical switching environment. It exist in the ESXi environment and is independent of the underlying hardware. NSX is an approach to networking that enables Data Center managers to create model for the underlying physical network. It has the ability to be deployed on Any IP network, including existing traditional networking models and next generation fabric architectures from any vendor.

NSX capabilities extend to the following functional services:

  • Logical switching – The logical switching capability of the NSX platform provides customers the ability to spin up isolated logical level 2 (L2) networks with the same flexibility and agility as that of virtual machines.
  • Logical Routing – The distributed routing capability of the NSX platform provides and optimized and scalable way of handling East-West traffic within a data center. The amount of East-West traffic in the data center keeps growing and the new collaborative, distributed, and service oriented application architectures of the SDDC demands higher bandwidth for server-to-server communication.
  • Logical Firewall – The NSX platform includes distributed kernel- enabled firewalling with line rate performance and virtualization. It also include identity aware with activity monitoring, among other network security features native to network virtualization.
  • Logical Load Balancer – This service offers distribution of workloads across multiple servers, as well as high availability of applications.
  • Logical Virtual Private Network – SSL VPN-Plus allows remote users to access private corporate applications. IP Sec VPN offers site-to-site connectivity between an NSX Edge instance and remote sites. L2 VPN allows you to extend your data center by allowing virtual machines to retain network connectivity across geographical boundaries.

 


Components of VMware vSphere 6.0 – part 3

The third part of the Data Center Virtualization – Components of VMware vSphere consist of the following :

  • Shared storage
  • Storage protocols
  • Data Stores
  • Virtual SAN
  • Virtual Volumes

Articles already published are :

  1. An introduction of Data Center Virtualization 
  2. Components of VMware vSphere 6.0 – part 1 which include an overview of Vsphere 6.0, its architecture, Topology and configuration maximums.
  3. Components of VMware vSphere 6.0 – part 2 which include an introduction to vCenter servers and its features.

Shared Storage

Shared storage consist of storage systems that your ESXi hosts use to store virtual machine files remotely. The hosts access the system over high speed storage network. It helps in operating VMs on different hosts. It allows multiple ESXi hosts to access the storage even if few hosts become unavailable.

Photo credits: VMware.com
Photo credits: VMware.com

Several of the vSphere features also require shared storage infrastructure to to work properly which include:

  • DRS
  • DPM
  • Storage DRS
  • High Availability
  • Fault tolerance

Storage Protocols

vSphere supports the following storage protocols:

  • Fibre channel – High speed network technology  that is primarily used to connect storage components over a SAN. Fibre channel solutions require  dedicated network storage devices that are not typically accessed through other LAN devices. Fibre channel is commonly used for vSphere VMFS Datastores and boot LUNs for ESXi. vSphere provides native support for fibre channel protocols and for fibre channel over Ethernet (FCoE). It supports fibre channel speeds from 2 Gbps to 16Gbps
  • Fibre channel over Ethernet – In FCoE, the fibre channel traffic is encapsulated into Ethernet frames and the FCoE frames are converged with networking traffic. By enabling the same ethernet link to carry both fibre channel and ethernet traffic, FCoE increases the use of the Ethernet Infrastructure. FCoE also reduces the total number of network ports used in the network environment.
  • iSCSI – uses Ethernet connections between computer systems or host servers, and high performance storage systems. iSCSI is commonly used for VMFS datastores. It does not require special purpose cables and can also be run over long distances. You can also do thin provisioning on iSCI LUNs, whereas this is not possible with NFS. ESXi provides native support for iSCSI through the following iSCSI initiators: Independent iSCSI initiators, Dependent iSCSI initiators and iSCSI software initiators
  • Network File System – NFS is an IP-based file sharing protocol that is used by NAS to allow multiple remote systems to connect to a shared file system. It uses the file-level data access and the target NAS device controls the storage device. NFS is the only vSphere supported NAS protocol which supports NFSv3 over TCP/IP along with simultaneous host access NFS volumes. You cannot initialize or format a NAS target from a remote server. The NAS server is responsible for the file system where the data is stored.
  • Local Storage – Can be internal hard disks located inside your ESXi host, or it can be direct attached storage. Local storage does not require a storage network to communicate with your host. You need a cable connected to the storage unit and, when required, a compatible HBA in your host.
  • Virtual Volumes – A new integration and management framework that virtualizes SAN/NAS arrays, enabling a more efficient operational model that is optimized for virtualized environments. Virtual volumes simplifies storage operations by automating manual tasks. It provides administrators with finer control of storage resources and data services at the VM level, simplifying the delivery of storage service levels to applications.

These storage protocols gives you the choice and flexibility to adapt to changing IT environments. Each storage options has its own strengths and weaknesses.

Datastores

In vSphere VM are stored in containers called datastores.These are logical volumes that allows you to organize the storage of your ESXi hosts and virtual machine. You can browse the datastores to download/upload files within the vSphere web client.

Photo credits: VMware
Photo credits: VMware

Data stores can also be used to store ISO images, VM templates and floppy images. Depending on the type of storage, datastores can be of the following type:

  • VMFS datastores – The vSphere VMFS format is a special high performance file system format that is optimized for storing virtual machines. You use the VMFS format to deploy datastores on block storage devices. A VMFS datastore can be extended to expand several physical storage. This feature allows you to pool storage and gives you flexibility in creating the datastore necessary for your virtual machines.
  • NFS datastores – You can use NFS volumes to store and boot virtual machines in the same way that you use VMFS datastores. The maximum size of NFS datastores depends on the support that an NFS server provides. ESXi does not impose any limit on the NFS datastores size.
  • Virtual SAN datastores – Virtual volumes virtualizes SAN and NAS devices by abstracting physical hardware resources into pools of capacity known as virtual datastores. The virtual datastores defines capacity boundaries, access logic and exposes a set of data services accessible to the virtual machines provisioned in the pool. Virtual datastores are purely logical constructs that can be configured on the fly, when needed, without disruption and don’t require formatting with a file system.

Virtual SAN

Virtual SAN is a distributed layer of software that runs natively as parts of the ESXi hypervisor. You can activate Virtual SAN when you create host clusters. Alternatively, you can enable virtual SAN on existing clusters.

Photo credits: VMware
Photo credits: VMware

The hosts in the virtual SAN need not be identical. Even the hosts within the virtual SAN cluster that have no local disks can participate and run their VM on the virtual SAN datastores. When enabled, virtual SAN works with the VM storage policy. It monitors and reports on policy compliance during the life cycle of the VM. If the policy becomes non-compliant because of a host, disk or network failure or workload changes, virtual SANs take remedial actions. Virtual SAN can be configured as hybrid or All flash storage.

Hybrid Storage – In a hybrid storage architecture, virtual SAN pools server attached hard disk drives (HDDs or SSDs) to create a distributed shared datastores that abstract the storage hardware to create a Software-Defined Storage Tier for virtual machines. Flash is used as a read cache / write buffer to accelerate performance and magnetic disk provide data persistance.

Photo credits: VMware
Photo credits: VMware

All-Flash Storage – In this architecture, Flash devices are intelligently used as a write cache, whilst SSDs provide data persistence and consistent fast response times. 

Photo credits: VMware
Photo credits: VMware

Virtual SAN is a separate paid offering and not included in vSphere.

Virtual Volumes

Virtual Volumes is a new virtual machine disk management and integrated framework that enables array based operations at the virtual disk level. It makes SAN and NAS storage system capable of being managed at a virtual machine level. With Virtual Volumes, most data operations are offloaded to the storage arrays.

Photo credits: VMware
Photo credits: VMware

Virtual Volumes eliminates the need to manage large number of LUNs or volumes per host. This reduces operational overhead whilst enabling scalable data services on a per VM-level.

Storage Policy Based Management (SPBM) is a key technology that works in conjunction with Virtual Volumes. This framework provides direct resource allocation and management of storage related services. Administrators can specify a set of storage requirements and capabilities for any particular virtual machine to match service levels required by hosted applications


Components of VMware vSphere 6.0 – part 2

As mentioned previously in my previous post on Components of VMware and vSphere 6.0 – Part 1, the aim of the article is to publish a continuous summary of the Data Center Virtualization exam. This article will focuss on the following points:

  • vCenter Server – Introduction
  • vCenter Server – Features

The vCenter Server – Introduction

The vCenter server is the hypervisor core management application of vSphere provides centralized management of vSphere virtual infrastructure. It allows administrators to ensure security and availability, simplifies day-to-day tasks and reduces complexity of managing virtual infrastructure.

vCenter server manages the essential functions of vSphere from any browser using vSphere web client. It provides simplified and integrated management of VMware hosts. It also simplifies management by assembling and automating out of the box work flows. In vCenter orchestrator, vCenter can restart failed virtual machines without any manual intervention. It monitors utilization across resource pools and allocates resources among VMs according to pre-defined rules. vCenter server integrates with the ecosystem partners to extend the capabilities of the virtual infrastructure.

The VMware PSC (Platform Resources Controller) is a component of vCenter server. It contains common infrastructure services such as vCenter single sign-on, VMware certificate authority, licensing and Server Reservation and Registration. This gives customers to single point to manage all vSphere roles and permissions along with licensing.

Photo credits: VMware
Photo credits: VMware

VMware PSC (Platform Resource Controller) has two models of deployments i.e; embedded and centralized. In Embedded, the PSC and vCenter server are installed on a single virtual machine. In a centralized model, the PSC and the vCenter server are installed on different virtual machine.

photo credits: VMware
photo credits: VMware

vCenter server – Features

vCenter server has the following features:

Certificate management – In vSphere 6.0, solution users (the users created) when a solution such as vCenter Server, vCenter Inventory service and so on is registered with vCenter single sign-on utilized as certificate endpoints. These users are issued certificates instead of individual services. This enables the services associated with a solution user to utilize the same certificate, substantially reducing the number of certificates required to manage in the environment. The VMware Certificate Authority (VMCA) is a root certificate authority (CA) that issues signed certificates to all vSphere 6.0 components via the solution users.

Alarms and Alerts – Alarms are notifications that are activated in response to an event, a set of conditions, or the state of an inventory object. Alarm can change state from mild warnings to more serious alerts as system conditions change, and can trigger automated alarm actions. This functionality is useful when you want to be informed or take immediate actions, when certain events or conditions occur for a specific inventory object, or group of objects.

Monitoring Features – vCenter server provides several tools to help you monitor your virtual environment and to locate the source of current and potential problems. It provides performance charts, storage reports and system log files to monitor your environment.

Template Management – The content library simplifies virtual machine template management and distribution by centrally managing virtual machine templates, ISO images and scripts. It also performs the replication of associated data from the published catalog to the subscribed catalog at other sites. As content are updated, old versions are automatically purged and replaced with a new version, offering life cycle management capabilities for virtual machine templates and related files.

Linked mode Deployment – vCenter server linked mode enables a common inventory view across multiple instances of the vCenter server. Linked mode provide a single pane of glass view across geographically separate vCenter servers. This deployment replicates licenses, permissions and roles across multiple vCenter services. Linked mode is automatically enabled for any vCenter server deployment.

PS: All of these materials are available freely on the VMware website which i made a resume to have a picture of what is being introduced in this module.