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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