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70-412: Configuring Advanced Windows
Server 2012 services
Chapter 1Configure and Manage High Availability
Objective 1.1: Configuring Network
Load Balancing
© 2013 John Wiley & Sons, Inc. 3
Availability• When a server goes down, it most likely
causes your company to lose money. o If your network contains an external website or
database that controls your sales, ordering, inventory, or production, server downtime can be detrimental to these business needs.
o If it is an internal server, it might not allow your users to perform their jobs.
o In either case, your company loses money either through lost revenue or lost productivity.
© 2013 John Wiley & Sons, Inc. 4
Fault Tolerance• To make a server more fault tolerant, you
should first look at what components are the most likely to fail and implement technology to make a system less likely to fail.
• Redundant components could include:o Disks: Use some form of RAID and hot spares.o Power supplies: Use redundant power
supplies.o Network cards: Use redundant network cards.
© 2013 John Wiley & Sons, Inc. 5
Network Load Balancing (NLB)
• Network Load Balancing (NLB) transparently distributes traffic across multiple servers by using virtual IP addresses and a shared name.
• With NLB, you gain fault tolerance and enhanced performance. It is often used with mission-critical web servers but can also be used with other types of servers.
© 2013 John Wiley & Sons, Inc. 6
Heartbeats• NLB can detect the failure of cluster nodes
by sending packets known as heartbeats. • NLB cluster heartbeats are transmitted
every second between nodes in the cluster.
• If a node misses five consecutive heartbeats, the node is automatically removed from the NLB cluster.
© 2013 John Wiley & Sons, Inc. 7
Convergence• When a node is added or removed from a
cluster, a process known as convergence occurs, where the cluster determines its current configuration by building a membership of nodes and mapping client requests based on the available nodes.
• Convergence can occur only if each node is configured with the same port rules.
© 2013 John Wiley & Sons, Inc. 8
Affinity• Affinity determines how the servers are
going to balance the load. • You use affinity settings when you use
multiple host filter mode.
© 2013 John Wiley & Sons, Inc. 9
Cluster Operation Mode
• On the Cluster Parameters tab, you configure the virtual IP address, subnet mask, and DNS name that the cluster will use.
• You also can configure the cluster operation mode, which specifies whether a multicast MAC address should be used for cluster operations.
Objective 1.2: Configuring Failover
Clustering
© 2013 John Wiley & Sons, Inc. 11
Failover Cluster• A failover cluster is a set of servers that work
together to increase the availability of services and applications.
• The clustered servers (called nodes) are connected through a network connection (physical or virtual) and by software.
• If one of the nodes fails, another node begins to provide services (a process known as failover).
• Failover clusters can be used for a wide range of network services including database applications such as Exchange Server or SQL Server, file servers, or network services such as Dynamic Host Control Protocol (DHCP) services.
© 2013 John Wiley & Sons, Inc. 12
Failover Cluster Components
• Nodeso Servers that make up the cluster and that run
the Cluster service. o They host the associated cluster resources and
applications. o In Windows Server 2012, a failover cluster can
have 64 physical nodes and can run 4,000 virtual machines on each cluster. • Windows Server 2008 R2 supported only 16
physical nodes and 1,000 virtual machines per cluster.
© 2013 John Wiley & Sons, Inc. 13
Failover Cluster Components
• Network: A common network that connects the cluster nodes. Three types of networks can be used in a cluster: public, private, and public-and-private.
• Cluster storage: A storage system that is shared between cluster nodes and usually connects using fiber channel or iSCSI.
• Clients: Computers (or users) that use the Cluster service.
• Cluster service: The service running on Windows servers that manages and coordinates cluster resources to provide high availability.
© 2013 John Wiley & Sons, Inc. 14
Quorum• A quorum is used with a failover cluster to
determine the number of failures that the cluster can sustain.
• If a quorum (the majority of the votes) is not reached, the cluster will stop running.
• Each voting element contains a copy of the cluster configuration, and the Cluster service works to keep all copies synchronized at all times.
© 2013 John Wiley & Sons, Inc. 15
Quorum Configuration• Quorum Configuration
o Node Majorityo Node and Disk Majorityo Node and File Share Majorityo No Majority (Disk Only)
• When using a witness disk, the disk must be at least 512 MB. It must be dedicated for cluster use and not assigned to a clustered role. It cannot be a volume that is a CSV.
Objective 1.3: Managing Failover
Clustering
© 2013 John Wiley & Sons, Inc. 17
Failover Clustering Roles
• Failover clusters provide high availability and scalability to many server applications (e.g., Microsoft Exchange, Microsoft SQL, and Hyper-V).
• Use the High Availability Wizard to configure a clustered role (formerly called a clustered service or application), which is a service or application that you make highly available.
© 2013 John Wiley & Sons, Inc. 18
General Use File Server Role
• File servers in a cluster can be configured for general use—General Use File Server—which is almost the same as it was in Windows Server 2008 R2.
• It provides a central location for users to share files or for server applications that open and close files frequently.
• It also supports SMB, Network File System (NFS), Data Deduplication, File Server Resource Manager, DFS Replication, and other File Services role services.
• The only significant difference between Windows Server 2008 R2 and Windows Server 2012 is that Windows Server 2012 supports SMB 3.0.
© 2013 John Wiley & Sons, Inc. 19
Scale-Out File Server• The Scale-Out File Server, introduced in
Windows Server 2012, can be used with a cluster. It is intended for application data such as Hyper-V VM files and for file shares that require reliability, manageability, and high performance.
• Unlike a General Use File Server cluster, the Scale-Out File Server cluster is an active-active failover cluster where all file shares are online on all nodes simultaneously.
• Although the Scale-Out File Server supports SMB, it does not support NFS, Data Deduplication, DFS Replication, or File Server Resource Manager.
© 2013 John Wiley & Sons, Inc. 20
Highly Available Virtual Machine
• One popular use of failover clusters is with Hyper-V to provide highly available virtual machines (VM).
• To make a VM highly available, the VM storage location must be on shared storage that all nodes can access. In addition, the storage needs to be configured as a CSV.
Objective 1.4: Managing Virtual
Machine Movement
© 2013 John Wiley & Sons, Inc. 22
Understanding Virtual Machine Movement
• For a server administrator, virtual machines are one of the best tools to use for providing functionality on demand.
• With relative speed and ease, you can deliver additional applications as soon as they are needed rather than waiting for the purchase of new hardware.
© 2013 John Wiley & Sons, Inc. 23
Live Migration• Live migration (LM) allows you to move the entire
VM or its storage from one physical host to another without interrupting your users.
• This process is sometimes referred to as a “shared nothing” migration because the storage is mirrored over the network to the destination server while the VM continues to run and provide network services.
• To perform an LM, follow these four steps:1. Configure LM prerequisites. 2. Configure LM security (constrained delegation , if
needed).3. Configure the source and destination computers for LM. 4. Move a running virtual machine or VM storage.
© 2013 John Wiley & Sons, Inc. 24
Move Options• The three options to move virtual
machines:o Move the VM’s data to a single location:
This is simplest.o Move the VM’s data by selecting where to
move the items: This provides the most options for where you can store the various components.
o Move only the VM: This requires shared storage and allows you to move the VM without moving the virtual hard disk.
© 2013 John Wiley & Sons, Inc. 25
Quick Migration• Windows Server 2012 includes way to move
a Live VM that is hosted in a cluster called quick migration (QM).
• Quick migration is another process of moving a running VM from one physical host to another. However, QM occurs within the confines of a cluster.
• Quick migration allows you to: o Consolidate physical servers o Maintain availability during maintenanceo Quickly restore services after service outages
© 2013 John Wiley & Sons, Inc. 26
Storage Migration• As VMs grow, they may outgrow their initial
storage. • Storage migration is yet another way to move live
VM data without disrupting users. • The three options are:
o Move the VM’s data to a single location: This is simplest.
o Move the VM’s data by selecting where to move the items: This provides the most options for where you can store the various components.
o Move only the VM: This requires shared storage and allows you to move the VM without moving the virtual hard disk.
© 2013 John Wiley & Sons, Inc. 27
P2V and V2V• A physical machine to virtual machine (P2V)
migration takes an existing physical computer and converts it into a virtual machine. o P2V migration can be performed with either Microsoft
System Center 2012 SP1 (SC12) – Virtual Machine Manager (VMM or SCVMM) or the Disk2vhd tool from the Microsoft Sysinternals website.
• A virtual machine to virtual machine migration (V2V) converts an existing virtual machine to a different file format. Currently, SCVMM supports migrations from VMware, XenServer, or OVF.