In this segment of my review of the Microsoft Windows Server 2003 Resource Kit Tools, we will be exploring the Confdisk.exe tool.
The Confdisk.exe -- Disk Configuration Utility -- is a tool that administrators can use to recover failed disks in a cluster. Typically, an administrator would use Confdisk in conjunction with the Cluster Recovery and Cluster Administrator tools due to the nature of cluster troubleshooting.
First, let's review server clusters, or nodes, per Microsoft:
"A server cluster is a group of independent computer systems, known as nodes, that work together to run a common set of applications and to provide a single system image to the clients and to the application. The computers are physically connected by cables and programmatically connected by clustering software. The nodes in a cluster remain in constant communication through the exchange of periodic messages, called heartbeats. If one of the nodes becomes unavailable as a result of failure or maintenance, another node immediately begins providing service (a process known as failover)."
Requirements:
Confdisk must be run on a server that belongs to the cluster.
This tool can be used in Windows Server 2003 Enterprise Edition and Windows Server 2003 Datacenter Edition.
Installation:
You can run Confdisk.exe on any system that has the reskit (Windows 2003 Resource Kit Tools) installed.
General use:
The Confdisk tool uses a .sif file, which an administrator needs to create before a cluster fails. The .sif file contains the necessary information to recreate the disk signature on the clusters hard disk. An administrator uses the Confdisk tool to create the sif file by referencing an ASR (Automated System Recovery) diskette. It uses the files on this diskette to populate the .sif file.
Per Microsoft:
"ConfDisk uses a .sif file to restore a cluster after a hard disk failure. If the .sif file is not created prior to the failure, ConfDisk does not have the information it needs to restore the cluster."
"Automated System Recovery (ASR) is a wizard that backs up the system state, system services and all disks associated with the operating system components; it also creates a floppy disk containing information about the backup that created the ASR set, the disk configurations (including basic and dynamic volumes), and how to accomplish a restore. When performing a restore, ASR reads the disk configurations from the floppy and restores all the disk signatures, volumes, and partitions on, at a minimum, the disks required to boot up. (It attempts to restore all the disk configurations, but under some circumstances, may not be able to)."
To use this utility:
Navigate to Start --> All Programs --> Windows Resource Kit Tools --> Command Shell
Type the following command: confdisk {/save SaveFile|/restore RestoreFile}
Parameters:
/save SaveFile - Specifies that the cluster configuration information be saved to SaveFile. SaveFile is created by ASR as a .sif file type. If SaveFile already exists, it will be overwritten with no warning.
/restore RestoreFile - Specifies that the configuration be restored from RestoreFile. RestoreFile is a file with a .sif file type.
Examples:
To save a configuration to a .sif file: confdisk /save c:\asr.sif
To restore a configuration from a .sif file: confdisk /restore c:\asr.sif
Here is a common disk replacement scenario from Microsoft: The Cluster service fails to start and generates an Event ID 1034 in the Event log after you replace a failed hard disk or change drives for the quorum resource.
Cause: If a hard disk is replaced, or the bus is reenumerated, the Cluster service may not find the expected disk signatures and consequently may fail to mount the disk.
Solution: Write down the expected signature from the Description section of the Event ID 1034 error message. Then follow these steps:
- Back up the server cluster.
- Set the Cluster service to start manually on all nodes, and then turn off all but one node.
- If necessary, partition the new disk and assign a drive letter.
- Use the Confdisk.exe tool to write that signature to the disk.
- Start the Cluster service and bring the disk online.
- If necessary, restore the cluster configuration information.
- Turn on each node, one at a time.
Note:Administrators need to create a .sif file before using Confdisk.
The Microsoft Windows Server 2003 Resource Kit Tools are a set of tools to help administrators streamline management tasks, such as troubleshooting operating system issues, managing Active Directory, configuring networking and security features, and automating application deployment. You can download the kit and see a list of tools provided at Microsoft's Web site.
About the author: Tim Fenner (MCSE, MCSA: Messaging, Network+ and A+) is a senior systems administrator who oversees a Microsoft Windows, Exchange and Office environment. He is also an independent consultant who specializes in the design, implementation and management of Windows networks.
