Business Continuity Solution
You should consider any sizable network in organic terms; dynamic, interconnected, impacted by internal and external forces and most important, subject to accidents and death. Your job as the IT administrator is to "protect and nurture" the organism with adequate authentication and virus protection and a framework of rules and procedures that minimize or eliminate threats. But how do you adequately prepare and protect against major, uncontrollable events such as earthquakes, hurricanes, fires, power outages and other human or natural accidents? In simple terms, you do what nature does-design with redundancy.
A broad selection of business continuity solutions was included with Novell Open Enterprise Server 1.0 including iFolder, Archive and File Versioning, and Cluster Services. With the release of Novell Business Continuity Clustering 1.1, it's time to review Novell Open Enterprise Server IT protection tools and highlight new capabilities.
Now supported on Linux, Novell Business Continuity Clustering helps protect your organic network with auto failover and redundancy in the event of localized area network deaths or segment dismemberment. Support for SMI-S, the Storage Management Initiative Specification, now ensures compatibility with hundreds of new storage devices. With Novell Business Continuity Clustering, resource vulnerability is eliminated and network and application service availability are ensured while compliance and failure risks are mitigated. With the simplicity and wide availability of clustering in Novell Open Enterprise Server, there's simply no reason why your organization's network shouldn't be cluster protected.
Novell Business Continuity Clustering - What Is It?
Novell Business Continuity Clustering is a high-availability solution that provides cluster site failover for "clusters to clusters" across geographical sites. Available on both Novell Open Enterprise Server-NetWare and now Novell Open Enterprise Server-Linux, Novell Business Continuity Clustering automates the configuration and management of high-availability server clusters that support network applications and services as well as data storage. It is tightly integrated with Novell eDirectory, ensuring that access rights and authentication structure are preserved along with applications and application data. Novell Business Continuity Clustering is also well integrated with other Novell products, such as iManager, enabling simple, remote and automated management and allowing third-party storage solutions to be fully utilized.
Here's how it works
Novell Business Continuity Clustering is built on Novell Cluster Services. In a nutshell, Novell Business Continuity Clustering takes the standard Novell Cluster Services implementation options and adds specialized software for configuration, synchronization and maintenance. A typical implementation has two distinct clusters in a "cluster of clusters" configuration where sites share the same eDirectory tree and each geographical site supports up to 32 servers.
In the event of disaster, selected cluster resources or all cluster resources can fail over from one cluster to another.
- integrates with SAN hardware devices to automate the failover process using the standards-based Storage Management Initiative - Specification (SMI-S) as well as the storage vendor's proprietary command line utilities.
- uses Novell Identity Manager technology to automatically synchronize and transfer cluster-related eDirectory objects from one cluster to another (search and replace strings are used to transform cluster resource load and unload scripts from one cluster to another)
- Novell Business Continuity Clustering provides the capability to fail over as few as one cluster resource, or as many as all cluster resources
- supports two to four clusters in the business continuity cluster for a total of 128 nodes working together to ensure a high level of service uptime
- includes intelligent failover that lets IT administrators do site failover testing as a standard practice
- supports active/active clusters where each cluster in the business continuity cluster can be hosting services that are in use by local users
- provides scripting capability for enhanced control and customization< /li>
- provides simplified business continuity cluster configuration and management using the browser-based iManager management tool
Unlike competitive solutions that attempt to build stretch clusters, where all nodes reside in the same cluster with failover to specific nodes, Novell Business Continuity Clustering uses a cluster of clusters approach. Each site has its own independent cluster of servers, and the clusters in each of the geographically separate sites are treated as "nodes" in a larger cluster, allowing a whole site to do fan-out failover to multiple other sites. Although this can currently be done manually with a cluster of clusters, Novell Business Continuity Clustering automates the system using eDirectory and policy-based management of the application resources and storage systems.
If your applications and data access are Internet- or Web-based, failovers can be completely seamless to users. By integrating iChain and ZENworks products, all services, applications and data can be rendered through the Internet, accommodating loss of service at one site with full access to the services and data using the Internet as the network backbone. Data and services continue to be available from the other mirrored sites.
A lower-cost cluster is possible by substituting iSCSI (SCSI protocols across IP networks) for more expensive Fibre Channel switches. Options for two-site or multi-site configurations are the same, and data block mirroring is accomplished with either SAN-based block replication, or host-based mirroring. In either case, snapshot technology can allow for asynchronous replication over long distances.
Installation and Configuration
Some Novell components must be installed in addition to Novell Business Continuity Clustering:
- Novell Cluster Services
- Novell Identity Manager (formerly DirXML)
- Novell eDirectory
Novell Business Continuity Clustering includes an Identity Manager driver template that is used to synchronize cluster resources between clusters.
Several options exist for data redundancy, including SAN-based and host-based mirroring. SAN-based mirroring is recommended and provided by several Novell certified SAN hardware manufacturers such as EMC, IBM, Xiotech, EqualLogic or any SMI-S-compliant device. Novell Business Continuity Clustering 1.1 fully supports SMI-S, thus letting you use more than 280 devices from 18 manufacturers.
You can also accomplish host-based synchronous mirroring using Novell Storage Services (NSS) by creating NSS-mirrored pools and cluster-enabling them. For real-time mirroring, link speeds should be 1GB or better, distances between sites should be 200 kilometres or less and the links should be dedicated.
Using Novell iManager, you can configure multiple clusters in the business continuity cluster at the same time. Do this through the Novell Business Continuity Clustering-specific Identity Manager drivers as well as Novell Business Continuity Clustering-specific policy that you define. Also use iManager for management operations such as viewing status, getting reports, and initiating or disabling cluster operations.
Special Considerations
Included with every copy of Novell Open Enterprise Server is a license to deploy any number of two-node clusters. This allows you to create clusters for small networks or for testing without any incremental expense. You can obtain additional nodes by purchasing additional licenses for Novell Cluster Services.
Also note that Novell Business Continuity Clustering does not perform data mirroring.
You must configure either SAN-based mirroring or host-based mirroring using Novell Storage Services separately. Also, clusters containing both NetWare and Linux servers are only supported in a business continuity cluster as a temporary means to convert a cluster from NetWare to Linux. Part of the temporary conversion state includes a restriction that only one mixed-node cluster can exist in your business continuity cluster. For example, Cluster A can have both NetWare and Linux nodes, but Cluster B cannot. All nodes in Cluster B must be either NetWare or Linux.
Configuring auto-failover requires a degree of forethought. Consider all factors that can trigger an auto-failover, for example, connection time-outs and switch maintenance, and which nodes are critical enough to merit failover. In most cases, you'll prefer to have a rule-based framework for when specific resources should be manually migrated as opposed to when a complete auto-failover should occur. Consider the probability and consequences of element failure of any of the following: primary cluster, secondary cluster, primary SAN, secondary SAN, inter-site SAN connectivity, and inter-site LAN connectivity. Also, only two clusters are supported if you use the auto-failover feature. In the future, Novell will release a support pack that provides auto-failover support for more than two clusters.
Novell Business Continuity Clustering protects your key business systems against downtime and disaster, and keeps your network and application resources alive and healthy. With Novell Business Continuity Clustering, you'll maintain 24x7x365 data and application availability to your users while still being able to perform system maintenance and upgrades. New functionality available with version 1.1 extends this protection to Linux systems and makes it much easier to manage and maintain mixed NetWare/Linux networks. The additional support of SMI-S significantly increases the number of hardware devices and vendors that you can integrate as part of your business continuity solution.
In summary, with Novell Business Continuity Clustering, you have the flexibility to design a redundant system that best serves the organic nature of your network. Whether you have a single site, main site with a remote failover site, or multiple sites with application and data redundancy needed for each, you can configure Novell Business Continuity Clustering to meet your requirements. You can further extend this flexibility with options for manual migration of resources, partial failover or full auto-failover. With Novell Business Continuity Clustering, continuous availability of critical business resources is possible, and you can easily implement and administer full-fledged business continuity plans to protect against human and natural disasters. If you have Novell Open Enterprise Server, you already have what you need to create a failover solution with the type of redundancy required to protect against any disaster.