Archive for the ‘MSCS’ Category

How to generate and correctly interpret Failover Cluster Log

July 2, 2011

Very often it is required to generate cluster log if the eventlog information’s are not enough to nail down your root cause and for getting a better understanding what is happening under the hood of your failover cluster.

Hereby are some useful articles and techniques for how to generate cluster logs and of course how to correctly read and interpret them:

Anatomy of a Cluster Log Entry

Techniques for Tracking the Source of a Problem

Interpreting the Cluster Log

Cluster Log Basics

Understanding the Cluster Debug Log in 2008

Windows Server 2008 and R2 Cluster Log Appears to Be Missing Gaps of Data

View Events and Logs for a Failover Cluster

TechNet Webcast: Failover Cluster Validation and Troubleshooting with Windows Server 2008 (Level 300)

Failover Clustering: Pro Troubleshooting in Windows Server 2008 (PPT)

How to create the cluster.log in Windows Server 2008 Failover Clustering

DBA 101: Collecting and Interpreting Failover Cluster Logs

Introduction to Cluster Diagnostics and Verification Tool for Exchange Administrators

How to turn on cluster logging in Microsoft Cluster Server (W2K3)

The meaning of state codes in the Cluster log

Failover Cluster Troubleshooting

Troubleshooting Cluster Logs 101 – Why did the resources failover to the other node?

Hope this helps to understand more what is going on under the hood of your failover cluster, especially in root cause analyses (RCA), test and/or proof-of-concept scenarios it is really helpful to be able to read and interpret the cluster logs.

Stay tuned Winking smile

Best Regards



KB266274 – How to Troubleshoot Cluster Service Startup Issues

April 7, 2008

When the Cluster service initially starts, it attempts to join an existing cluster. For this to occur, the Cluster service must be able to contact an existing cluster node. If the join procedure does not succeed, the cluster continues to the form stage; the main requirement of this stage is the ability to mount the quorum device.
These are the steps in the startup process in order:

• Authenticate the Service account.

• Load the local copy of the cluster database.

• Use information in the local database to try to contact other nodes to begin the join procedure. If a node is contacted and authentication is successful, the join procedure is successful.

• If no other node is available, the Cluster service uses the information in the local database to mount the quorum device and updates the local copy of the database by loading the latest checkpoint file and replaying the quorum log.

Reference KB266274

How to turn on Cluster logging on MSCS

April 7, 2008

If you need to troubleshoot cluster issues, you can turn on the verbose logging for the cluster service "CLUSTER.LOG" which is located %WINDIR%Cluster

To set the System environment variables, follow these steps:

1. In the System tool in Control Panel, click the Environment tab.

2. Click an entry in the System Environment Variable window.

3. Click to clear the Variable and the Value text boxes.

4. Type ClusterLog in the Variable box, type path\cluster.log in the Value box, and then click Set, where path is the drive and folder to store the Cluster Server log file.
Note: The recommended default path in Windows 2000 and later is %SystemRoot%\Cluster. For example, C:\WinNT\Cluster\Cluster.log.

5. Type ClusterLogLevel in the Variable box, type the value that you want in the Value box (a list of values follows), and then click Set.
The value that you type in the Value box determines what logging functions the Cluster service performs. You can type any one of the following values:

0=No logging

1=Errors only

2=Errors and Warnings

3=Everything that occurs

Note: The CLUSTERLOGLEVEL variable only defines the output to the screen when you start the Cluster service by using the /Debug switch. It does not affect the contents of the Cluster.log file.

6. Click OK.

7. Restart your computer for Cluster service to read the variables correctly.

More details @ KB168801

Enhanced Disk Resource Private Properties Using Cluster Server

November 11, 2007

Enhanced Disk Resource Private Properties Using Cluster Server;en-us;223023&sd=tech


Configurable Windows Cluster Heartbeat

November 11, 2007
An update is available that adds a file share witness feature and a configurable cluster heartbeats feature to Windows Server 2003 Service Pack 1-based server clusters

Configurable cluster heartbeats

The configurable cluster heartbeats feature enables you to configure cluster heartbeat parameters. This may help avoid unnecessary cluster failovers. These failovers occur because of a temporary network problem that may cause packets to be dropped or delayed. The configurable cluster heartbeats feature may help in an environment where cluster nodes are geographically dispersed.

The current cluster heartbeat algorithm sends a heartbeat message every 1.2 seconds from each interface on each cluster node. This message is sent to each interface on the same cluster network. Therefore, each cluster node both sends a heartbeat message every 1.2 seconds and expects to receive a heartbeat message every 1.2 seconds. If two consecutive heartbeats from the same interface are missed, the Cluster service suspects that an interface failure may have occurred. If six consecutive heartbeats are missed from all the interfaces on a node, the Cluster service suspects that a node failure may have occurred.

More here :





April 24, 2007

Quorom as local disk for Testing

November 11, 2007

Standard Quorum

As mentioned above, a quorum is simply a configuration database for MSCS, and is stored in the quorum log file. A standard quorum uses a quorum log file that is located on a disk hosted on a shared storage interconnect that is accessible by all members of the cluster.

Note: It is possible to configure Server clusters  to use the local hard disk on a server to store the quorum, but this is only supported for testing and development purposes, and should not be used in a production environment. Each member connects to the shared storage through some type of interconnect (for example, SCSI or Fibre Channel), with the storage consisting of either external hard disks (usually configured as RAID disks), or a storage area network (SAN), where logical slices of the SAN are presented as physical disks.

Note: It is important that the quorum uses a physical disk resource, as opposed to a disk partition, as the entire physical disk resource is moved during failover.


Copyright Microsoft Corpporation – Windows 2003 Server Clusters: Quorum Options Document

Windows 2000 Cluster and LUN 0 ;-)

November 11, 2007

Identifying LUNS in Windows 2000 or NT 4.0

Voyager’s SAN is being used to host the storage requirements of several different systems, including mainframe storage requirements. This storage diversity demands specialized configuration of the disks (or logical devices) that are grouped and presented as basic disks to the Windows 2000 operating system.

Voyager found that Windows 2000 must locate a disk assigned as LUN 0 before it will scan and identify any disks with LUNs greater than 0. In order to correlate certain logical devices and LUN schemes, Voyager chose to assign a small disk or logical partition as LUN 0. This allowed Windows 2000 to always identify other non-zero LUNS.

For additional information go to the following web pages on the Microsoft web site (see Microsoft Knowledge Base article 162471):;en-us;162471&sd=tech.

How to change Cluster Service Account (Exchange) ?

July 13, 2007


Note this does not apply to the service acct used for Exchange.

  1. 1. Log on to one of the cluster nodes using an account with admin rights on both (all) cluster nodes.
  2. 2. Have a domain admin change the password for the service account.
  3. 3. Open a CMD prompt on the cluster node.
  4. 4. Type the following (without quotes)  “cluster /cluster:CLUSTERNAME /changepassword /skipdc” (where CLUSTERNAME is the name of the cluster.

When prompted enter and confirm the new password. This will update the password for the cluster account on all nodes.

Alternatively, they can just create a new domain account and then use the following article to set permissions properly:

269229 How to manually re-create the Cluster service account;EN-US;269229