Windows 2000 Server System Administration Handbook P2

Increased Reliability, Availability, and ScalabilityReliability, availability, and scalability are important parameters of network operating systems. An operating system should be able to work 24 hours a day, seven days a week, and the administrator should not be required to perform a reboot after every configuration change; in addition, the operating system should be able to correct itself when problems occur. Finally, an operating system should be able to grow in order to meet the demands of expanding businesses. Reliability is the measure of the consistency with which a computer runs its applications and services. Windows 2000 Server provides many reliability...
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Windows 2000 Server System Administration Handbook P26 Chapter 1 • The Windows 2000 System Administration Migration Path improving the system’s overall reliability and scalability, providing a pow- erful Internet and application server, and providing a powerful end-to- end management solution, while reducing total cost of ownership.Increased Reliability, Availability, and Scalability Reliability, availability, and scalability are important parameters of network operating systems. An operating system should be able to work 24 hours a day, seven days a week, and the administrator should not be required to perform a reboot after every configuration change; in addition, the operating system should be able to correct itself when problems occur. Finally, an operating system should be able to grow in order to meet the demands of expanding businesses. Reliability is the measure of the consistency with which a com- puter runs its applications and services. Windows 2000 Server pro- vides many reliability solutions, including: s Core operating system services s Fault tolerance s Disaster recovery s System recovery and updates s Reliable storage s Avoidance of outages and reboots Core Operating System Services Windows 2000 Server provides these core operating system services: s Error handling and protected subsystems s Recoverable file system s Automatic restart The operating system is designed to correct itself by managing errors without crashing the entire computer. The operating system The Windows 2000 System Administration Migration Path • Chapter 1 7ensures that a fault in one program will not affect other runningprograms, by using protected subsystems that isolate programs inmemory. Windows 2000’s new NTFS 5.0 file system logs all disk I/O oper-ations as individual, unique transactions, so the system providesfault tolerance by undoing or redoing transactions after a system isbrought back up after having suffered a disk failure. It is to be hoped that your system will never have to restart itselfafter a system failure; however, if a failure does occur, Windows2000 Server can be set to restart itself automatically. This capabilityis important if no administrators are present when the systemcrashes. Because many servers have enormous amounts of RAM,dumping the contents of RAM could take quite a while, thusincreasing downtime. Fortunately, Windows 2000 is designed torestart more quickly than it was able to do in earlier versions,thanks to a new “Write kernel information only” dump option.Fault ToleranceWindows 2000 Server increases fault tolerance by providing: s Support for various RAID levels s Distributed file system (Dfs) Windows 2000 supports the various levels of RAID that adminis-trators may require; it includes support for disk mirroring or diskduplexing (RAID level 1), and disk striping with parity (RAID level 5).Windows 2000 Server also supports RAID level 0, which is stripingwithout Parity; however, this offers no data redundancy. Another feature, the Distributed file system, improves fault toler-ance by providing increased data availability and load balancingwhen it is integrated with Active Directory. Dfs makes finding andmanaging information much easier by implementing a single name-space for miscellaneous file system resources, which allows sharesto be maintained redundantly among multiple servers.8 Chapter 1 • The Windows 2000 System Administration Migration Path Disaster and System Recovery Windows 2000 Server provides methods for disaster and system recovery: s Tape backup and UPS support s Repair Command Console s Safe mode boot s System File Protection Windows 2000 includes an enhanced and powerful tape backup utility, and also includes support for uninterruptible power supplies through a UPS service, which sends alerts in the event of a power failure. In addition, the service is capable of safely shutting down the system before the battery power in the power supply is depleted. Another useful utility allows access to the NTFS file system for authorized users in case the server becomes inaccessible. Using the boot floppies, you can access this utility, called the Repair Command Console. Before Windows 2000, many administrators would resort to installing a parallel copy of Windows NT into a dif- ferent directory in order to gain access to the files system. The other option was to install NT on a FAT partition so access could be gained to the file system through the use of a Windows 98 boot disk. Fortunately, the Windows 2000 Repair Command Console pro- vides an alternate way to safe ...