Some Thoughts on Clustering SQL Server Virtual Machines. On my blog post Virtualizing SQL on VMware Reference List, Oscar Zamora (Blog | Twitter) asked the following question in a comment: As a virtualized instance has the benefit of "failing over" to another physical box, would you consider clustering a virtualized instance?
The answer to this question more than I want to write up in a comment, so I decided instead to blog my response. Since at least ESX 3, VMware has provided a number of high availability features in their enterprise server virtualization product. A detailed listing of the HA features available in VSphere 4 can be found in the vSphere Availability Guide. In this post I’ll talk about the most popular ones and the ones that VMware marketing uses to try to convince people that VMware HA solves all of their High Availability needs. High Availability and DRS Clusters ESX hosts can be clustered together providing high availability from the hardware failure of a host for the guests running inside of the cluster. Fault Tolerance. Virtualizing SQL on VMware Reference List. I’ve been managing SQL Server virtualized in production environments for nearly five years now, and in that time, I’ve had to do a significant amount of reading/learning about VMware as a hypervisor so that I could properly track down performance problems and in a lot of cases, prove to vendors that the problem wasn’t virtualization.
It wasn’t very long ago that nobody supported virtualization, including Microsoft, despite the fact that it generally wasn’t the cause of problems. Lately I’ve seen more people virtualizing SQL Servers and asking questions about running SQL Server in a virtualized environment and in a lot of cases, when the platform selected is VMware, I can answer their questions by pointing them to one of the many whitepapers I’ve read over the last few years. To make this easier, and to share what I consider to be important references for VMware I am going to list them in this blog post by category.
Getting Started with SQL Server 2008 R2 Failover Clustering. When there is hardware or software failure of a server, the applications or clients connecting to the server will experience downtime.
When a SQL Server instance is configured to be an FCI (instead of a standalone instance), the high availability of that SQL Server instance is protected by the presence of redundant nodes in the FCI. Only one of the nodes in the FCI owns the WSFC resource group at a time. In case of a failure (hardware failures, operating system failures, application or service failures), or a planned upgrade, the resource group ownership is moved to another WSFC node. This process is transparent to the client or application connecting to SQL Server and this minimize the downtime the application or clients experience during a failure. The following lists some key benefits that SQL Server failover cluster instances provide: In a production environment, we recommend that you use static IP addresses in conjunction the virtual IP address of a Failover Cluster Instance. Setup for Failover Clustering.
Understanding MS DTC Resources in Windows Server 2008 Failover Clusters. Updated: April 11, 2008 Applies To: Windows Server 2008 In Windows Server 2008, the Microsoft Distributed Transaction Coordinator (MS DTC) component provides support for active/active clusters in which a clustered MS DTC resource coordinates distributed transactions across a Windows failover cluster group. Clustering MS SQL Server 2008 R2 on VMware Virtual Windows Server 2008 R2 – 3. Hi folks This is the third and the last part of our article series about MS SQL Server 2008 R2 clustering and untill now we completed the creation of virtual machines and Windows clustering on them.
In this last part, I will install MS SQL Server 2008 R2 on these virtual clustered machines. But first of all, I want to talk a little bit about MS SQL Server clustering options. With the release of MS SQL Server 2008 product (I refer it as SQL throughout the article), Microsoft introduced two installation options for it on a clustered environment. These are; Integrated installation and Advanced/Enterprise installation.
Table 1: Installation phases In my scenario, I will prefer the first method which is Integrated Installation. Because I installed Windows Server 2008 R2 as the operating system, I don’t need any hotfix/service pack requirements to install for SQL deployment. Note: If you try to install SQL without MS DTC, you will receive a warning message like Figure 1. Installing a SQL Server 2008 R2 Failover Cluster. To install a SQL Server failover cluster, you must create and configure a failover cluster instance by running SQL Server Setup.
This topic explains the elements of a failover cluster, as well as important information about naming a failover cluster instance. It also describes basic steps for installing a failover cluster.