Lesson 12 – NETWORK SERVERS

Distinguish between servers and workstations. Choose servers for Windows NT and Netware. Maintain and troubleshoot servers. OVERVIEW

Servers incorporate several features not found in workstations. Servers serve up data/services to a number of users. DISTINGUISH BETWEEN SERVERS AND WORKSTATIONS

Server processors Bus capabilities RAM Disk subsystems Features of servers

Disk topologies: RAID I2O Server state monitoring Hot-swap components Features of servers

Xeon processors are: Optimized for server-type duties. More suited to a multiprocessor system. Server processors

Intel Clones: AMD K6 series of processors DEC Alpha HP PA-RISC PowerPC Server processors

Data on the server is moved in lots. A bus is the backbone for data transfer. Network cards, processors, and system’s memory are connected to the bus. The bus can handle five times more data than other system components. Bus capabilities

Types: Nonparity Parity Error Checking and Correcting (ECC) RAM

Nonparity: Eliminates the parity bit. Is unable to detect memory error. Is a cost-cutting technique. RAM

Parity: Uses an extra bit for every byte to store a checksum of the byte’s contents. Stops the system and reports an error if the checksum does not match when memory is read. The system is unable to correct errors. RAM

Error Checking and Correcting (ECC): Detects up to two bits of errors. Corrects one bit of error automatically. Provides added protection. RAM

Is the slowest component. Is most likely to be a bottleneck. A reliable disk configuration is of great importance. Disk subsystems

Redundant Array of Inexpensive Disks: Uses many disks to do the work of one. Spreads a server’s data across many disks. Disk Topologies: RAID

Disks can independently find data and send it to be assembled. Performance increases as you add more disks. The chance of disk failure increases as data is spread across disks. Disk Topologies: RAID

Intelligent I/O: Moves I/O processing from the computer’s processor to the disk controller. Relieves some of the computer’s central processor load. I2O

Higher-end servers monitor: Proper fan operation System voltage Memory errors In-case temperature Operating system hangs Computer case opening Server state monitoring

Can be replaced while the system operates. Are limited to disks, power supplies, and fans running in a redundant configuration. Hot-swap components

Defining needs Selecting servers Purchasing the system Installing servers CHOOSE SERVERS FOR WINDOWS NT AND NETWARE

Considerations: What is the life of the server? What job will the server perform? How many users will the server support? What are the needs of users? Defining needs

Considerations: How reliable must the server be? Will you use clustering for the server? How safe must data on the server be? Defining needs

Considerations: What are your backup plans? How do you plan to back up the server? How could demands on the server change? Will the server work with existing hardware? Defining needs

Compatibility is the basic prerequisite. The server should meet Novell’s/Microsoft’s hardware requirements. Selecting the server

The server brand should have: An established service organization. High-quality support. Technical support databases. In-house engineering. Selecting the server

Purchasing the system

Test server hardware. Read server documentation. Use automated tools provided by the manufacturer. Install an NOS. Installing servers

Run potential NLMs, NT services and processes, or UNIX/Linux daemons together during testing. Check for updates provided before installation. Installing servers

Reduce failures Resolve failures MAINTAIN AND TROUBLESHOOT SERVERS

Use reliable, tested servers and components. Reduce the number of server tasks (when possible). View the server’s error logs. Reduce failures

Install management software. Install special software that supports hot-swap in RAID. Shut down/restart the server periodically. Reduce failures

Take backups/test restores before a server goes into production. Preserve purchase data. Retain configuration details. Resolve failures

List software needed to rebuild the server. Maintain contact information for service on the server. Document configuration changes and error messages. Document anything special about the server/disk drive configuration. Resolve failures

Distinguish between a server and a workstation: Server processors Bus capabilities RAM Disk subsystems Disk Topologies: RAID I2O Server state monitoring Hot-swap components SUMMARY

Choose servers for Windows NT and Netware: Defining needs Selecting the server Purchasing the system Installing servers Summary

Maintain and troubleshoot servers: Reduce failures Resolve failures Summary