Windows IT Pro is the authoritative and independent resource for windows nt, windows 2000, windows 2003, windows xp. Features a collection of resources and magazines for windows IT professionals.
  
  
  Advanced Search 


June 06, 2008

Q. What are the Windows Server 2008 quorum models?


A Web Exclusive from FAQ for Windows
John Savill
Clustering
InstantDoc #99354
FAQ for Windows
Email this Article
Printer Friendly
Reader Comments
Digg This
Del.icio.us
RSS
Subscribe to Windows IT Pro | See More Clustering and Load Balancing Articles Here | Reprints | Or get the Monthly Online Pass—only $5.95 a month!

A. Windows Server 2008 has a single-quorum model based on a number of cluster voting elements. By allocating these votes differently, Server 2008 clusters have four quorum modes.
  • Node Majority—There's no file-share witness or disk witness and votes are assigned only to nodes. More than 50 percent of the nodes must be available to make quorum. Node majority works best if you have an odd number of nodes. I recommend the Node Majority mode if you have an odd number of nodes, and you have a multi-site cluster, a cluster with no shared storage, or a single-node cluster. Figure 1 shows an example of a Node-Majority quorum.

  • Node and Disk Majority—Nodes and a shared disk get votes. This configuration allows a loss of half the nodes, providing the disk witness is available, or over half the nodes are available without the disk witness being available. I recommend Node and Disk Majority mode if your cluster has an even number of nodes. Figure 2 shows an example of a Node-and-Disk-Majority quorum.

  • Node and File Share Majority—The same as Node and Disk Majority, except the shared disk is replaced with a file-share witness. I recommend a Node and File Share majority mode if you have multi-site cluster, an even-node cluster, a cluster with no shared storage, or a two-node cluster. Figure 3 shows an example of a Node-and-File-Share-Majority quorum.

  • No Majority: Disk Only—The disk witness must be available to have quorum, but the number of available nodes doesn't matter. If you have a four-node cluster and only one node is available, but the disk witness is available, you have quorum. If the disk witness isn't available, then even if all four nodes are available you can't have quorum. I never recommend the No-Majority: Disk-Only mode. Figure 4 shows how the disk witness must be available to have quorum.

    The table in Figure 5 summarizes my recommended options.

    End of Article



    Reader Comments
    Figure 4 gets a 404 Page not found error

    Rick4IT June 10, 2008 (Article Rating: )

    Thanks for bringing the error to our attention! I'll notify the editor and we'll correct it ASAP.

    AnneG_editor June 10, 2008 (Article Rating: )

    You must log on before posting a comment.

    If you don't have a username & password, please register now.




Top Viewed ArticlesView all articles
Friday at PASS Europe 2006

Kevin talks about the closing day of the event and shares a funny Microsoft film. ...

The Memory-Optimization Hoax

Don't believe the hype. At best, RAM optimizers have no effect. At worst, they seriously degrade performance. ...

Escape From Yesterworld

Kevin points you to the funniest SQL Server website ever! ...
Windows OSs Whitepapers Why SaaS is the Right Solution for Log Management

Are You Satisfied?

A Preliminary Look at Deployment Plans for Microsoft Windows Vista
Related Events Check out our list of Free Email Newsletters!
Windows OSs eBooks Understanding and Leveraging Code Signing Technologies

A Guide to Windows Certification and Public Keys

SQL Server Administration for Oracle DBAs
Related Windows OSs Resources Become a VIP member of the Windows IT Pro community!
Get it all with the VIP CD and VIP access. A $500+ value for only $279!

Subscribe to Windows IT Pro!
Solve your toughest technical problems with our experts and access 10,000 + articles online. 30% off

Monthly Online Pass - Only $5.95!
Get instant access to 10,000+ articles from Windows IT Pro Magazine!

TechNet Virtual Labs
Evaluate and test Microsoft's newest products.

Job Openings in IT

ADS BY GOOGLE SPONSORED LINKS FEATURED LINKS

IT Connections
Dive into the new Microsoft platforms and products you implement and support with the experts from Microsoft, TechNet Magazine, Windows ITPro and industry gurus. There are 70+ sessions and interactive panels with networking opportunities.

Attention User Group Leaders...
Announcing the eNews Generator—a FREE HTML e-newsletter builder for user group leaders. Build your HTML and text e-newsletters in minutes and add Windows IT Pro & SQL Server Mag articles alongside your own message!.

Master SharePoint with 3 eLearning Seminars
Learn how to build a better SharePoint infrastructure and enable powerful collaboration with MVPs Dan Holme and Michael Noel. Register today!

Get SQL Server 2008 at WinConnections
Don’t miss Microsoft Exchange and Windows Connections conferences, the premier events for Microsoft IT Professionals in Las Vegas, November 10-13. Every attendee will receive a copy of SQL Server 2008 Standard Edition with one CAL.



Interested in Email Encryption?
Read about the advantages of identity-based encryption in this free report.

Order Your SQL Fundamentals CD Today!
Learn how to use SQL Server, understand Office integration techniques and dive into the essentials of SQL Express and Visual Basic with this free SQL Fundamentals CD.

Virtualization Congress Oct. 14-16 in London
Don't miss Virtualization Congress, the premiere EMEA conference dedicated to hardware, OS and application virtualization. Oct. 14-16.
Windows IT Pro Home Register FAQ for Windows WinInfo News
Europe Edition About Us Contact Us/Customer Service Media Kit Affiliates / Licensing  
SQL Server Magazine Office & SharePoint Pro Windows Dev Pro IT Job Hound ITTV
IT Library Technical Resources Directory Connected Home Windows Excavator Windows SuperSite 
 
 Windows IT Pro is a Division of Penton Media Inc.
 Copyright © 2008 Penton Media, Inc., All rights reserved. Terms and Use | Privacy Statement | Reprints and Licensing