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How to change a Passive cluster to an Active Cluster
How to change a Passive cluster to an Active Cluster
Currently, we have a Active/Passive Cluster: SQL CLU1/SQL CLU2. Towards the end of the year, we will be adding a new database which will be extremely important to our organization. We would like to run this Database on SQL CLU2 and if SQL CLU2 would fail it would immediately go to SQL CLU1. To that end, I would like to know how to change our passive cluster (SQL CLU2) to an active cluster?
Thank you,
CaptSky
Answers
- Hello CaptSky
The term active/active is misleading. What you will have is a dual active/passive cluster.
You install the new active/passive cluster in exactly the same way as you installed the original. They are completely independent. This then gives you an 'active/active' config. FWIW, Microsoft have phased out this terminology because it can be misleading with multiple-host clusters (>2 nodes)
HTH
Ewan
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If this post answers your question, click the 'Mark As Answered' link below. It helps others who experience the same issue in future to find the solution.- Marked As Answer byCaptSky Friday, October 30, 2009 2:03 PM
All Replies
- Hello CaptSky
The term active/active is misleading. What you will have is a dual active/passive cluster.
You install the new active/passive cluster in exactly the same way as you installed the original. They are completely independent. This then gives you an 'active/active' config. FWIW, Microsoft have phased out this terminology because it can be misleading with multiple-host clusters (>2 nodes)
HTH
Ewan
If you have found this post helpful, please click the 'Vote as Helpful' link (the green triangle and number on the top-left).
If this post answers your question, click the 'Mark As Answered' link below. It helps others who experience the same issue in future to find the solution.- Marked As Answer byCaptSky Friday, October 30, 2009 2:03 PM
- So, what you are telling me is that I will have to rebuild the Passive Cluster from scratch and set it up as an Active Cluster. Is that correct?
Thanks,
CaptSky
Hi,
You don't have to rebuild your cluster.
Ewan means that you have to install a second SQL instance to your cluster and move it's resources to passive node. Then you have active-active cluster.
BR,
JoukoK- Hi Joukok,
Okay, I'm a little confused. I already have a passive node - I want to make my passive node an Active node. Perhaps you meant to say, move it's resources to active node. Do I install the Second Instance over the passive mode and make it active? - All answers were talking about SQL Server failover cluster multi-instance. To my understanding, CaptSky is only asking for an automatic failover to SQLCLU1 when SQLCLU2 fails. This is a two-node cluster. So the current configuration(single instance failover cluster) can support this.
To test the failover can be done manually:
1. Open "Administrative tools" -> "Failover Cluster Management" (I am referring to Windows 2008 Server here as an example, Win 2003 is similar)
2. In the "Failover cluster manager", Right click the group which your SQL Server belongs to, and select "Move this service or application to another node". And confirm you are going to do the move.
3. This is the manual operation to test your failover cluster configured correctly and failover works fine.
To test the failover automatically, turn off SQLCLU2 to simulate a failure on SQLCLU2. The SQL Server instance will automatically start up and run on the other node, SQLCLU1.
Note: If this is the production system, the above test could induce a minute to hours of down-time depends on the real-time workload of your system. The failover is just one minute or so but the database recovery time, relying on the workload, varies from seconds to hours. Be careful! - Hi Zhen-Yu
I'm not sure I would advocate testing a production failover just yet...
CaptSky, if my original understanding is correct, you have one active SQL installation on a 2-node cluster. One of these nodes is active and one is passive at any one time. You now want another SQL installation, so you can have one active SQL engine on one node and one active SQL engine on the other node. If either engine fails, it comes back up on the other node.
If that is the case, then you do a brand new cluster installation, which will build a separate SQL cluster resource group, and this gives you two active/passive clusters. If the active SQL engines are on different physical nodes, you have made your passive node active, achieving your goal.
If this doesn't describe your scenario, post back with some more detail and we can try to help further.
HTH
Ewan
If you have found this post helpful, please click the 'Vote as Helpful' link (the green triangle and number on the top-left).
If this post answers your question, click the 'Mark As Answered' link below. It helps others who experience the same issue in future to find the solution. - Think of a cluster in terms of nodes (machines) and SQL Server instances (Virtual Servers). that probably makes it easier for you. Examples:
You probably today have two nodes and one instance:
Nodes: A B
Instances:
X (preferrably on A, and if A fails then run on B).
What you want to something like below:
Nodes: A B
Instances:
X (preferrably on A, and if A fails then run on B).
Y (preferrably on B, and if B fails then run on A).
Here's a slightly more complex setup with three nodes and three instances:
Nodes: A B C
X(A, C, B)
Y(B, C, A)
Z(B, C, A)
As you see, you max mix instances and nodes very flexible in a cluster and terms like "active" and "passive" has little meaning regarding cluster setup.
Tibor Karaszi, SQL Server MVP http://www.karaszi.com/sqlserver/default.asp http://sqlblog.com/blogs/tibor_karaszi - Okay,
Let me try again. We have SQLCluster1 which is an ACTIVE CLUSTER, we also have SQLCluster2 which is a PASSIVE CLUSTER.
How do I change SQLCluster2 to an ACTIVE CLUSTER? I don't want to add another NODE, I only want 2 NODES.
Does this help?
CaptSky - Hi CaptSky
You are using the terminology, well, incorrectly. There is no such thing as an active cluster or a passive cluster. I think you have one cluster with 2 nodes, a passive node and an active node. Is that correct?
No response so far has suggested that you should add another node. Tibor only used a 3-node cluster setup to illustrate why active/passive naming doesn't really work well beyond 2 nodes. But that's an aside.
Can you take a look at my posts and see if they apply to your case?
The following whitepaper on SQL Clustering might be helpful, though it is quite detailed in places.
http://download.microsoft.com/download/6/9/D/69D1FEA7-5B42-437A-B3BA-A4AD13E34EF6/SQLServer2008FailoverCluster.docx
Regards
Ewan
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