Another new feature of Windows Server 2003 is Automated System Recovery (ASR). ASR is more a recovery feature than a fault-tolerance tool, although in an effort to increase server availability in the event of a disaster, ASR can be a valuable component to the overall solution. The primary goal of ASR is to accelerate recovery time in the event of the loss of a server by bringing a nonbootable system to a state from which a backup and restore application can be executed. This includes configuring the physical storage to its original state, and installing the operating system with all the original settings. Improving the Disaster Recovery ProcessPrior to Windows Server 2003, the process by which a lost server is rebuilt and recovered was a time-consuming ordeal. The old methods usually resembled the following process:
With ASR, many of the steps in the old model are eliminated or automated. The new recovery method now proceeds as follows :
ASR is broken down into two parts : backup and restore. The backup portion is executed through the Automated System Recovery Preparation Wizard located in Backup. The Automated System Recovery Preparation Wizard backs up the System State data, system services, and all disks associated with the operating system components . It also creates a floppy disk, which contains information about the backup, the disk configurations (including basic and dynamic volumes ), and how to accomplish a restore. The restore portion of ASR is initiated by pressing F2 during the text portion of Windows Server 2003 setup. When the ASR restore process is initiated, ASR reads the disk configurations from the floppy disk and restores all the disk signatures, volumes, and partitions on the disks required to start your computer. ASR then installs a simple installation of Windows and automatically starts to restore from backup using the backup ASR set created by the Automated System Recovery Preparation Wizard. A Full Data Backup ASR is primarily involved with restoring the system; it does not back up data. Always include a full data backup in disaster recovery solutions. To take advantage of ASR in a disaster recovery solution, systems must meet a limited set of requirements:
Using ASR to Recover Cluster ServicesASR can be used to recover a cluster node that is damaged because of corrupt or missing system files, cluster registry files, or hard disk failure. To prepare for an ASR recovery of clustered servers, run the Automated System Recovery Preparation Wizard on all nodes of the cluster and make sure that the cluster service is running when the Automated System Recovery backup is run. Make sure that one of the nodes on which the Automated System Recovery Preparation Wizard is run is listed as the owner of the quorum resource while the wizard is running. In addition to having the ASR disk, recovering a damaged node in a cluster requires the Windows Server 2003 installation media, backup media containing data backup, and potentially the mass storage driver for the new hardware. With these in hand, perform the following steps to recover a damaged cluster node:
Restoring a Disk Signature to a Damaged Cluster Disk If you are restoring a disk signature to a damaged cluster disk, power down all other cluster nodes except the one on which you are performing the ASR restore. This cluster node must have exclusive rights to the damaged cluster disk. |