| Because hardware does occasionally fail, and in the real world operating systems do have problems, a server recovery plan is essential, even though it may never be used. The last thing any administrator wants is a server failure to occur and to end up on the phone with Microsoft Technical support telling him to restore the server from backup when he does not have a plan ready. To keep from being caught unprepared, the administrator should have a recovery plan for every possible failure associated with Windows Server 2003 systems. Restoring Versus Rebuilding When a complete system failure occurs, whether it is because of a site outage, a hardware component failure, or a software corruption problem, the method of recovery depends on the major goal the administrator is trying to accomplish. The goal is to get the server up and running, of course, but behind the scenes many more questions should be answered before the restore is started: How long will it take to restore the server from a full backup? If the server failed because of software corruption, will restoring the server from backup also restore the corruption that actually caused the failure? Will reloading the operating system and applications manually followed by restoring the system state be faster than a full restore?
Loading the Windows Server 2003 operating system and applications can be a relatively efficient operation. This ensures that all the correct files and drivers are loaded correctly, and all that needs to follow is a system state restore to recover the server configuration and restore the data. One of the problems that can occur is that, upon installation, some applications generate Registry keys based on the system's computer name, which can change if a system state restore is performed. Other applicationsfor example, Exchange Server 2003can be restored using a /disasterrecovery installation switch and do not need the server's system state restore, just the original computer name and domain membership, as long as computer and user certificates are not being used. The key to choosing whether to rebuild or restore from backup is understanding the dependencies of the applications and services to the operating system and having confidence in the server's stability at the time of the previous backups. The worst situation is attempting a restore from backup that takes several hours, only to find that the problem has been restored as well. Manually Recovering a Server When a complete server system failure is encountered and the state of the operating system or an application is in question, the operating system can be recovered manually. Locating the system's original configuration settings is the first step. This information is normally stored in a server configuration document or wherever server configuration information is kept. Because each system is different, as a general guideline for restoring a system manually, perform the following steps: 1. | Install a new operating system on the original system hardware and disk volume, or as close to the original configuration as possible. Be sure to install the same operating system versionfor example, Windows Server 2003 Enterprise or Standard Server.
| 2. | During installation, name the system using the name of the original server but do not join a domain.
| 3. | Do not install any additional services during installation and proceed by performing a basic installation.
| 4. | After the operating system completes installation, install any additional hardware drivers as necessary and update the operating system to the latest service pack and security patches. To reduce compatibility problems, install the service packs and updates as outlined in the server configuration document to ensure that any installed applications will function as desired. During a restore is not the time to roll out additional system changes. The goal is to get the system back online, not to upgrade it.
| 5. | Using the Disk Management console, create and format disk volumes and assign the correct drive letters as recorded in the server build document.
| 6. | If the server was originally part of a domain, you must first reset the computer account using the AD users and computers console and join the domain afterwards. This will ensure that permissions and group membership previously granted to this computer remain intact.
| 7. | Install any additional Windows Server 2003 services as defined in the server build document.
| 8. | Install any Microsoft server applications following any special recovery processes and restore application data immediately following the application restore.
| | | 9. | Install any third-party applications and restore configurations and data as necessary.
| 10. | Test functionality, add this system to the backup schedule, and start a full backup.
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Note If certificates were issued to the previous server for secure data communication, the new server must enroll with the Certification Authority (CA) for a new certificate before encrypted communication can occur.
Restoring a Server Using a System State Restore When an operating system fails and cannot be started, a restore of the entire server may be necessary. If system volumes and data volumes exist on the same disk, performing an Automated System Recovery (ASR) restore will wipe out the entire disk, and both the system and data will need to be restored. In many cases, an ASR restore is not necessary; recovering only the system volume and system state is necessary. After this process is complete, restores of the applications and application data should proceed. To recover a system using a clean installation and a previously backed-up system state, follow these steps: 1. | Shut down the original server.
| 2. | Install a new operating system on the original system hardware and disk volume, or as close to the original configuration as possible. Be sure to install the same operating system versionfor example, Windows Server 2003 Enterprise or Standard Server.
| 3. | During installation, name the system using the name of the original server but do not join a domain.
Note If the machine is joined to the original domain during the clean installation, a new security identifier (SID) will be generated for the machine account. A system state restore after this would restore an invalid computer SID, and many services and applications will fail. | 4. | Do not install any additional services during installation and proceed by performing a basic installation.
| 5. | After the operating system completes installation, install any additional hardware drivers as necessary and update the operating system to the latest service pack and security patches. To reduce compatibility problems, install the service packs and updates as outlined in the server build document to ensure that any installed applications will function as desired.
| | | 6. | Using the Disk Management console, create and format disk volumes and assign the correct drive letters as recorded in the server build document.
| 7. | After the installation, restore any necessary drivers or updates to match the original configuration. This information should be gathered from a server configuration document (server build document). Then reboot as necessary.
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After all the updates are installed, restore the previously backed-up system state data; afterward, restore any additional application or user data. System State Restore This section outlines how to restore the system state to a member or stand-alone Windows Server 2003 system. To restore the system state, perform the following steps: 1. | Click Start, All Programs, Accessories, System Tools, Backup.
| 2. | If this is the first time you've run Backup, it will open in Wizard mode. Choose to run it in Advanced mode by clicking the Advanced Mode hyperlink.
| 3. | Click the Restore Wizard (Advanced) button to start the Restore Wizard.
| 4. | Click Next on the Restore Wizard Welcome screen to continue.
| 5. | On the What to Restore page, select the appropriate cataloged backup media, expand the catalog selection, and check System State. Click Next to continue.
| 6. | If the correct tape or file backup media does not appear in this window, cancel the restore process. Then, from the Restore Wizard, locate and catalog the appropriate media and return to the restore process from step 1.
| 7. | On the Completing the Restore Wizard page, click Finish to start the restore.
| 8. | When the restore is complete, review the backup log for detailed information and click Close on the Restore Progress window when finished.
| 9. | Reboot the system as prompted.
| 10. | When the system restarts, log in using an account with Local and/or Domain Administrator rights as necessary.
| 11. | After the system state is restored, install any additional applications and data if necessary.
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Restoring a System Using ASR Restore When a system has failed and all other recovery options have been exhausted, an ASR restore can be performed, provided that an ASR backup has been previously performed. The ASR restore will restore all disk and volume configurations, including redefining volumes and formatting them. This means that the data stored on all volumes needs to be restored after the ASR restore is complete. This restore brings a failed system back to complete server operation, except for certain applications that may require special configurations after the restore. For example, the Remote Storage service data needs to be restored separately. Note An ASR restore re-creates all disk volumes, but if a new or alternate system is being used, each disk must be of equal or greater size to the disks on the original server. Otherwise, the ASR restore will fail.
To perform an ASR restore, follow these steps: 1. | Locate the ASR floppy created for the failed node or create the floppy from the files saved in the ASR backup media. For information on creating the ASR floppy from the ASR backup media, refer to Help and Support from any Windows Server 2003 Help and Support tool.
| 2. | Insert the Windows Server 2003 operating system media in the CD-ROM drive of the server you are restoring to and start the installation from this CD.
| 3. | When prompted, press F6 to install any third-party storage device drivers if necessary. This includes any third-party disks or tape controllers that Windows Server 2003 will not natively recognize.
| 4. | Press F2 when prompted to perform an Automated System Recovery.
| 5. | Insert the ASR floppy disk into the floppy drive and press Enter when prompted. If the system does not have a local floppy drive, one must temporarily be added; otherwise, an ASR restore cannot be performed.
| 6. | The operating system installation proceeds by restoring disk volume information and reformatting the volumes associated with the operating system. When this process is complete, the operating system will restart after a short countdown, the graphic-based OS installation will begin, and the ASR backup will attempt to reconnect to the backup media automatically. If the backup media is on a network drive, the ASR backup reconnection will fail. If it fails, specify the network location of the backup media using a UNC path and enter authentication information if prompted.
| 7. | When the media is located, open the media and click Next and then Finish to begin recovering the remaining ASR data.
| 8. | When the ASR restore is complete, if any local disk data was not restored with the ASR restore, restore all local disks.
| 9. | Click Start, All Programs, Accessories, System Tools, Backup.
| 10. | If this is the first time you've run Backup, it will open in Wizard mode. Choose to run it in Advanced mode by clicking the Advanced Mode hyperlink.
| | | 11. | Click the Restore Wizard (Advanced) button to start the Restore Wizard.
| 12. | Click Next on the Restore Wizard Welcome screen to continue.
| 13. | On the What to Restore page, select the appropriate cataloged backup media, expand the catalog selection, and check desired data on each local drive. Click Next to continue.
| 14. | On the Completing the Restore Wizard page, click Finish to start the restore. Because you want to restore only what ASR did not, you do not need to make any advanced restore configuration changes.
| 15. | When the restore is complete, reboot the server if prompted.
| 16. | After the reboot is complete, log on to the restored server and check server configuration and functionality.
| 17. | If everything is working properly, perform a full backup and log off the server.
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Restoring the Boot Loader File When a Windows Server 2003 system is recovered using an ASR restore, the boot.ini file may not be restored. This file contains the options for booting into different operating systems on multiboot systems and booting into the Recovery Console if it was previously installed. To restore this file, simply restore it from backup to an alternate folder or drive. Delete the boot.ini file from the C:\ root folder and move the restored file from the alternate location to C:\ or whichever drive the boot.ini file previously was located on. |
