Novell NetWare and Dell Clusters: An Upgrade Case Study
By Tim Bicknelle (August 2002)
To address the demands of growing business, a manufacturing company sought to upgrade its IT system. The company migrated from the Novell® NetWare® 4.11 to the Novell NetWare 6 operating system. It also deployed two DellTM PowerEdgeTM 2550 servers in a cluster configuration, each with a Dell PowerEdge Expandable RAID Controller (PERC) that connects to the Dell PowerVaultTM 210S RAID array. The implementation of this hardware and software enhanced application performance and established a reliable, highly available environment.
Industrial and Tractor Limited is a Worcester, UK-based manufacturer of tubes and related products for major equipment manufacturers. To keep pace with ever expanding and increasing business loads, the company decided to upgrade its IT systems. The server systems, although reliable, were reaching the end of their lifespan and system utilization was steadily increasing.
The company relies heavily on its IT systems both to perform routine business functions, such as word processing and e-mail, and to run an advanced manufacturing control system, which adheres to stringent deadlines for customers. Developed in-house, this manufacturing control system serves as a central data store for several manufacturing components, including:
- A sub-LAN that controls 13 Computerized Numerical Control (CNC) tube-forming machines
- Four multi-axis-coordinate measuring machines
- A computer-controlled zinc electroplating line and associated effluent disposal arrangements
The company's LAN infrastructure was based on a mirrored server pair running the Novell® NetWare® 4.11 operating system with System Fault Tolerance, level III (SFT IIITM ), and a separate server running NetWare 4.11 to provide backups to DDS3 (125 m) DAT tape (see Figure 1 ).
Figure 1. Industrial and Tractor LAN before upgrading to NetWare 6 cluster
Each server of the mirrored pair resided in a separate building on the Industrial and Tractor campus. The buildings were linked by multimode fiber to provide data transfer between buildings. Multimode fiber also connected the link cards that are a fundamental part of the NetWare 4.x SFT III mirroring capability. Each building had the same set of 10/100 Mbps Category 5 data cabling and 10 Mbps Switched Ethernet, also linked by multimode fiber. This design—one mirrored server, one set of cabling, and client systems in each building—maximized redundancy and, over four years, proved resilient.
Two other company buildings, unreachable by fiber, used wireless devices to connect to the corporate e-mail and manufacturing systems and provide two-way file and print access.
Upgrade requirements for a growing business
Industrial and Tractor sought new IT systems that would maintain the current level of redundancy while incorporating well-tested hardware and software and providing reliability, speed, and simplicity of use and management. The company required a 24x7 solution that would provide little or no interruption to business operations.
A new IT infrastructure to meet upgrade requirements
ITNS, an IT consulting firm, helped Industrial and Tractor develop a new IT solution based on DellTM hardware and Novell software. Novell NetWare software was chosen for its proven reliability, redundancy capabilities, manageability, and affordability. Prior positive experiences with Dell servers and workstations encouraged Industrial and Tractor to stay with Dell hardware.
The hardware implementation
For its new IT system, Industrial and Tractor installed two Dell PowerEdgeTM 2550 rack-mounted servers. Features of the PowerEdge 2550 include the following:
- Two Intel® Pentium® III processors
- 1 GB RAM
- Two 15,000 rpm 18 GB drives
- A 2U form factor
Each server has an on-board Dell PowerEdge Expandable RAID Controller (PERC) to run the Novell NetWare 6 operating system at RAID-1 and a separate cluster-aware RAID controller to connect to the Dell PowerVaultTM 210S external RAID array, which has twelve 15,000 rpm 18 GB drives running at RAID-5.
The PowerEdge 2550 servers also include an on-board Broadcom® Gigabit BaseT interface, which is used with a Cisco® Catalyst® 3500 Series XL switch to upgrade the LAN and provide a gigabit backbone for the servers.
For backups, the company deployed a Dell PowerVault 110T Linear Tape-OpenTM (LTOTM ) backup unit, which connects to an Adaptec® SCSI controller in one server and uses VERITAS Backup ExecTM for NetWare. This device has a 100 GB native (200 GB compressed) backup capacity and can back up data at a theoretical rate of 54 GB/hour native (108 GB/hour compressed).
To house the new hardware as well as the current switch/hub infrastructure, Dell supplied a full-height rack enclosure with a pull-out, flat panel monitor; a keyboard; a KVM (keyboard, video, mouse) switching unit; and an APC® uninterruptible power supply (UPS) for the entire rack. Figure 2 shows the company's LAN after deploying this new hardware.
Figure 2. Industrial and Tractor LAN after upgrading to NetWare 6 cluster
Because the main manufacturing application that Industrial and Tractor uses is disk-intensive, the company implemented twelve 15,000 rpm 18 GB drives rather than three 10,000 rpm 72 GB drives. In most cases, including environments that use the PERC 3/Dual Channel (PERC 3/DC), the more spindles (drives), the better the performance. Read performance improves and, in multi-user environments, write performance is also likely to increase.
The software implementation
Industrial and Tractor decided to continue using a Novell NetWare-based platform because of the proven reliability of the outgoing NetWare 4.11 SFT III operating system. In the last four years, the company experienced no unplanned downtime. In fact, the servers were shut down only for routine maintenance or because of power outages caused by maintenance operations. NetWare provides 24x7 computing access for users and enables scheduled maintenance for hardware and software upgrades with no downtime. Therefore, the logical path for the company's IT system was to upgrade to the Novell NetWare 6 operating system.
The NetWare 6 operating system includes Novell Cluster ServicesTM 1.6 and Novell Storage ServicesTM 3.0 software. Novell Cluster Services is a built-in clustering tool that provides near- continuous access to storage. Novell Storage Services works with Novell Cluster Services to help manage storage environments. Supporting up to 32 servers per cluster and up to 32 processors in each server, Novell Cluster Services enables a company to accommodate escalating storage needs and to increase resources within the cluster. Because NetWare 6 supports multiprocessor configurations, dual processors were used in the Dell PowerEdge 2550 servers.
To maintain the current level of redundancy, Industrial and Tractor deployed a two-node NetWare 6 cluster. Using the cluster-aware PERC, each PowerEdge 2550 server connects to the SCSI Enclosure Management Module (SEMM) on the external storage. No additional software from Dell is necessary.
Clustering capabilities of NetWare 6
The external storage was divided into two logical storage devices, allowing both servers in the cluster to share storage access. Each server was configured to use one particular logical storage device, and the company's data and applications were split between the two devices. When a user requests data or accesses an application on one logical storage device, that request is served by one of the two servers in the cluster pair. If another user accesses data on the other logical storage device, the second server in the cluster serves this request.
Both servers are always in use, creating an active/active cluster. This type of cluster configuration can deliver twice the performance capabilities of a traditional active/passive cluster configuration, in which one server acts only as a standby or failover device. Also, because the servers are configured as a cluster, either server can seamlessly serve each logical data device so that users will not experience any downtime if a server fails. No downtime occurred when a server in the cluster was switched off during testing.
Novell NetWare 6 also provides server management tools. Each server can be seamlessly managed by using the traditional, JavaTM -based NetWare utilities or a typical Web browser, either over the LAN or WAN.
Figures 3 , 4 , and 5 show examples of the NetWare 6 Web-based server management utilities. These utilities and several others are included with NetWare 6 and can be accessed, with correct permissions, from any up-to-date Web browser.
Figure 3. Cluster resources and configuration screen
Figure 4. Server health status screen
Figure 5. Cluster status screen
Migration methodology for the new infrastructure
The Novell NetWare 4.11 operating system, deployed in the original Industrial and Tractor LAN, used the Internetwork Package Exchange/ Sequenced Packet Exchange (IPX/SPXTM ) protocols. The clustering services in Novell NetWare 6 require Transmission Control Protocol/ Internet Protocol (TCP/IP) instead of IPX/SPX, because each cluster logical disk resource has its own IP address.
In the new Industrial and Tractor LAN configuration, the cluster server pair accesses the shared storage using TCP/IP only, but serves clients using IPX/SPX, TCP/IP, or both, via the gigabit switch. These servers provide TCP/IP settings for clients via Dynamic Host Configuration Protocol (DHCP).
Several new client workstations were built into the LAN lab and configured with the company's standard office and manufacturing applications. To test compatibility, some workstations ran only IPX/SPX and some ran only TCP/IP. The tests indicated that only TCP/IP was necessary. To minimize LAN overhead and management, the company decided to migrate all users to TCP/IP.
Tests of the main manufacturing database showed that the database ran 20 times faster on the new hardware and software configuration. The manufacturing application tests also displayed a dramatic increase in speed, especially for sequential disk reads (see Figures 6 and 7 ). The current client level was appropriate, but an updated Broadcom Gigabit driver was implemented as a precaution.
Figure 6. Application speed before the migration
Figure 7. Application speed after the migration
Although the NetWare 4.11 queue-based printing worked seamlessly across the former server pair, the printers were migrated to the NetWare 6 Novell Distributed Print ServicesTM (NDPS® ) software, which is cluster-enabled to provide "queue-less" printing for all users.
An IT system poised for growth
By upgrading its IT infrastructure, Industrial and Tractor was able to improve system performance and prepare for future growth. The migration from Novell NetWare 4.11 to NetWare 6 was aided by the implementation of a Dell cluster configuration. The IT systems could remain redundant and thus highly reliable, and the company could maintain its 24x7 operation.
Tim Bicknelle (email@example.com) is a technical consultant at ITNS, a UK-based multinetwork-accredited LAN and WAN solutions provider. He is a Novell Certified NetWare Engineer.
FOR MORE INFORMATION
Dell clusters: https://www.dell.com/cluster
Industrial and Tractor: http://www.intrac.co.uk
Novell Cluster Services: http://www.novell.com/products/clusters/ncs