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DISASTER MANAGEMENT
IT disasters can come in many formsfloods, fires, earthquakes, tidal waves, and war are some dramatic examples. More common, less dramatic disasters involve the loss of a boot sector, accidental removal of operating system files, power supply interruption, hard drive crashes, and theft of equipment.
Automatic System Recovery
When a system loses its boot sector, critical operating system files, or other data vital to base-level function, the logon processes must be restored. Thus, the first thing automatic system recovery (ASR) does is restore this configuration information as partition structure and file system type. Windows Server 2003 system files are restored with the appropriate hierarchy. The Windows Server 2003 Ntldr and Ntdetect .com files are rebuilt if necessary. Once this is complete, system logon is possible. Then ASR attempts to recover user and auxiliary system files.
CREATING AN ASR SAVESET
To use this important recovery technology, an ASR Saveset must be created as follows:
Open the Backup and Restore Wizard from the Start Accessories System Tools Backup menu or the Ntbackup command-line utility. Select Advanced Mode from the opening wizard screen.Select the Automated System Recovery and Preparation wizard.Select the destination for the ASR Savesetusually a CD-ROM or diskette set.Click Finish.
If you must attempt to repair a nonbootable system, boot from the ASR Saveset diskettes or CD-ROM you created as just discussed. The screens lead you though a logical set of steps. At one stage you must decide to conduct either a fast repair, which automatically attempts to repair items, or a manual repair, which gives you direct control over the process. Unless you are very sophisticated, we recommend the use of the fast repair so that standard approaches are uniformly applied.
Manual Recovery with the Advanced Options Menu
Advanced Options is an alternative boot menu that is invoked by pressing F8 during the initial boot sequence. It provides several alternative approaches to the repair or recovery of a Windows Server 2003 system, as follows:
Safe Mode.
The safe mode executes a minimal version of Windows Server 2003 and runs essential services only. You can run it as the default with explorer.exe enabled, with basic networking, or with the command prompt (cmd.exe is loaded instead of explorer.exe). Local applications can be run in safe mode, but the screen resolution will be 640 x 480 and 16 colors by default. Use this mode as it was used in earlier versions of Windows NT and Windows 9x to repair problems manually.
Enable Boot Logging.
If this option is selected, it will create a file called ntbtlog.txt that records all boot-related activity. The file is stored at the beginning of the system's root directory and can be reviewed if boot sequence issues, such as bad drivers, occur.
Enable VGA Mode.
This was part of the normal boot menu in Windows NT. It is in the Advanced Options menu in Windows Server 2003 because it is not something that would be regularly selected. Use this option primarily to correct video display options set during a normal session that somehow render the display output unreadable. Once new sets are in place, you can reboot the system.
LastKnownGood Configuration.
Windows Server 2003 stores a new copy of a system's configuration. Copies of previous configurations are numbered sequentially and stored, and the LastKnownGood Configuration is then applied if the current configuration is faulty. Chapter 3 discusses using the Registry Editor to view and modify Registry entries. However, there is no need to use the Registry Editor to apply the LastKnownGood Configuration. When this option is selected from the Advanced menu, follow the commands presented and note all warnings. This process will reverse all nonsecurity-related configuration items.
The Command-Line Recovery Console
Another alternative in recovery is the command linebased Recovery Console, which can be used in either normal or safe mode environments. To install the Recovery Console, type the following from the command prompt or Run menu:
<cd designation>:\i386\win32 /cmdcons
The Recovery Console is a character-based environment that looks very much like MS-DOS. It permits you to perform a great many command-line tasks, including starting and stopping services. To terminate the Recovery Console type exit and press ENTER. Please note that this will also reboot the system.Because it provides direct control, the Recovery Console is probably the preferred method of experienced system administrators. Commands can be selected as needed by the administrator without the intervention of wizards or other actions that are not visible.
Emergency Repair Disk
The creation of an emergency repair disk (ERD) is a prudent action for any system administrator. Although highly unlikely, it is possible for critical Windows Server 2003 files to be lost or corrupted. The ERD can be used to restart the system so that these files can be restored. The ERD is created through the Backup utility by copying the following hidden system files to a formatted floppy disk:
Ntldr
Ntdetect.com
Ntbootdd.sys
Boot.ini
Fault Tolerance for Disaster Protection
Fault-tolerant systems are an important first line of defense in protecting data from system failures. As discussed earlier, RAID-5 and mirrored environments are two methods that are well supported by Windows 2000/Windows Server 2003. In Chapter 17 we examine a more expensive but extremely viable fault-tolerant approach known as system clustering. Refer to these sections for additional information on how to apply fault tolerance to your disaster recovery plan.
Uninterrupted Power Supply Management
Power failures happen in any jurisdiction and, along with power spikes and lightning, can destroy sensitive electronic equipment. This is why a relatively small investment can avert disaster. An uninterrupted power supply (UPS) provides sufficient power to permit you to gracefully shut down Windows Server 2003 systems in a power failure and guards against electrical storms and power spikes. The analysis of UPS systems by make and model is outside the scope of this book, but we recommend them. Their configuration is through Control Panel Power Options UPS tab.
