Parsing Windows 2008 Failover Clusters

A failover cluster (that is, a server cluster) is a combination of separate computers that improve the combination of application and service availability. The collection servers (ie nodes) are connected together by cable or software. If one of the nodes fails, the other node in the cluster takes over the task of the failed node through a process called failover, ensuring the least impact on the service. Failover clusters are typically used by IT staff who need to increase availability for critical service applications. In Windows Server 2008, the purpose of the failover cluster was to simplify the cluster and make them more secure and stable.

I. New Features of Failover Clustering

1. New Confirmation Wizard Features

In order to fully realize the benefits of high availability, all configurations must be carefully performed. , including servers, networks and storage. The new Failover Cluster Installation and Configuration Confirmation Wizard for Windows Server 2008 enables users to confirm whether the system, storage, and network configuration is suitable for integration. Some of the tests performed by the new validation wizard include:

Node testing to verify that the server is running the same operating system version and that the same software update has been made.

Network testing to determine if a planned cluster network meets specific needs, such as whether there are at least two separate subnets for network redundancy

storage tests, and analyzes whether the storage is properly stored Configured so that all shared disks can be read through all cluster nodes and to confirm that the storage meets specific needs.

2. Increased scalability of large volume data

Windows Server 2008 includes support for clustered storage of globally unique identifiers (GUIDs) or GUID partition tables (GPTs). Unlike master boot record (MBR) disks, GPT disks can have partitions larger than 2000GB and built-in redundancy. GPT has more advantages than MBR because it allows up to 128 partitions per disk and supports 18 alphabytes of data, allowing initial and backup partitioning of redundancy and supporting unique disks. With the partition ID.

Second, Failover Cluster Improvements

Windows Server 2008 Failover Clustering includes the following improvements to cluster configuration, management, and operations:

Improved cluster setup and migration : The simplified Cluster Setup Wizard enables users to complete cluster setup in one go. It also implements scriptable scriptability for the cluster to automate the configuration process. The migration process for existing clusters has also been simplified. Resource group settings can be made from a cluster running Windows Server® 2003 and applied to a cluster running Windows Server 2008.

Simplified management interface: After the wizards and interfaces have been improved, management tasks have been simplified and administrators have been able to centrally manage applications without having to focus on their clusters.

Improved stability and security for increased usability. The way clusters interact with storage has been improved, so quorum resources are no longer a single point of failure.

Improved network connectivity and security: Network health and security are improved by integrating Ipv6 with a DNS (Domain Name System) server that does not rely on legacy NetBIOS (Network Basic Input Output System) At the same time, other improvements in network connectivity have made the enterprise network more stable and more secure.

1. Server Management Console

To simplify cluster management, the cluster management interface has been improved to allow administrators to focus on application and data management rather than cluster management. The new interface is based on task settings and is more intuitive, with wizards that help administrators with complex operations. Windows Server 2008's new fault management cluster simplifies the following management and operational tasks:

Improved interface: The user interface is based on task settings, and the wizards help administrators complete complex operations before making the current Setting up a cluster role, such as setting up a print device server role, can be done in a few simple steps. The new cluster management tool can be used to view all cluster roles, making configuration options an intuitive, task-based menu setting.

Quickly add cluster resources to the configuration: The improved cluster management interface also makes it easier to perform shared tasks such as high availability.

Solving cluster problems: Windows' event tracking feature replaces cluster logs, allowing administrators to easily collect, manage, and report on events that occur on the cluster.

Use the Volume Mapping Copy Service to get backups: Full integration with the Volume Mapping Copy Service makes it easier to configure backup and recovery clusters.

Manage the viewing of shared folders in a cluster: The system provides a view of the shared storage, as well as a view of the shared folders, which makes it easier for users to understand which folders are clustered and can Make a failover to another node and see which shared folders belong to a single local node and cannot fail over.

Additionally, Windows Server 2008 also supports command line and Windows Management Instrumentation (WMI) options for failover clustering.

2, improved stability

Windows Server 2008 has a failover clustering feature that improves the cluster architecture and improves the quality of service provided to users. One of the most notable changes is the way the system maintains "arbitration". Arbitration is a cluster configuration database that determines which nodes are active and which are standby. It is used to enable a single node to provide the required applications and services when a node is down. If the interconnect between the cluster nodes is lost, the problem recovery protocol is enabled to avoid split-brain. When the interconnect is lost, the resource owner of the node becomes the cluster and the sole owner of all resources, avoiding the occurrence of split brain. Then this unique owner will make all the resources available to the customer. When a node with arbitration fails, the existing node will decide who will control the device.

Improvements to Failover Clustering enable administrators to configure clusters through the two cluster modes available in previous versions of Windows:

Quorum Disk Mode: A separate disk is used as a decision Part of the cluster continues to run "Voters"

The majority node setting model: The cluster will continue to run only if the majority of the nodes are running well and interconnected.

On Windows Server 2008, the hybrid operation of these two modes is the default configuration, so that the advantages of both modes can be achieved. For example, in a two-node cluster, the cluster can continue to run even if the quorum disk fails and is completely unavailable. Administrators do not have to deal with complex arbitration configurations, which are automatically configured during cluster setup. In this new hybrid mode, each node has a replicated quorum resource, so a failure in the quorum disk does not cause the cluster to fail.

3, Storage Integration

Windows Server 2008 Failover Clustering improvements in storage integration have resulted in significant improvements in functionality and reliability compared to previous server cluster releases. The main performance is:

Dynamically add disk resources: When the resource is online, the dependency of the resource can be modified, which means that the administrator can add the disk without interrupting the application that will use the disk.

The performance and stability of data storage has improved: Windows Server 2008 has been improved with persistent retention and new ways to manage shared files. It no longer uses SCSI bus resets that can cause SAN outages. The failover clustering of Windows Server 2008 keeps the disk from being unprotected, meaning that the volume is less likely to be corrupted. Failover clustering also improves disk lookup and recovery and supports three types of storage connections: Serial Attached SCSI (SAS), and Fibre Channel.

Easier Disk Maintenance: Many improvements have been made to the maintenance model, making it easier for administrators to run tools to check, repair, back up or restore disks while reducing the impact on the cluster.

4, Network Connectivity and Security

Windows Server 2008 Failover Clustering improves network connectivity and security performance compared to previous versions, enabling users to:

Use Ipv6 fully integrated with failover clustering: Failover clustering fully supports Ipv6 for node-to-node and node-to-client communication.

Using Domain Name System (DNS) instead of relying on legacy NetBIOS: Simplifies the transfer of server information blocks and means that users no longer need Winwos Internet Name Service (WINS) and NetBIOS name resolution.

Increased reliability through other improvements to network connectivity: Administrators can associate network name resources with multiple related IP addresses so that when IP addresses are available, network names are also available. In addition, when the node transmits and receives "frequency" to confirm that each node is still available, a more reliable Transmission Control Protocol (TCP) is used instead of the less reliable User Data Graph Protocol (UDP). Br>

Improved Security: Failover Clustering Security Improvements include:

o New Security Mode: Windows Server 2008 protects the improved security model, where the cluster service runs on the LocalSystem built-in account In the environment, security and protection of account passwords are enhanced.

o Audit: Administrators can use the audit to capture user information about reading the cluster and read time information.

o Encryption: The Windows Server 2008 runtime administrator sets the internal node interconnect to encrypted.

Nodes on different IP subnets: Nodes in a cluster no longer need to be on the same IP subnet, thus increasing flexibility. This improvement is especially important when the cluster is geographically extended and the location becomes flexible.

Summary:

Failover clustering in Windows Server 2008 provides an easy-to-use solution for businesses that need to deliver critical applications and services. The new configuration features make high-availability failover clusters easier to generate and configure, and the new management interface reduces operational complexity and expense through a unified management failover cluster interface.