January 30, 2015 at 7:55 am
I have two standalone production servers, each running a single instance. I was tasked to make these two existing nodes a clustered server (active/active). I have built clustered servers in past where no instances existed before, and have joined nodes to it. The question I have how you build a cluster to utilize existing instance and make it the primary? Going through building a cluster, you need to add features and instance name to use for building the cluster, I am not sure if it is feasible to use an existing instance and make it a primary cluster node?
January 30, 2015 at 10:49 am
lsalih (1/30/2015)
I have two standalone production servers, each running a single instance. I was tasked to make these two existing nodes a clustered server (active/active). I have built clustered servers in past where no instances existed before, and have joined nodes to it. The question I have how you build a cluster to utilize existing instance and make it the primary? Going through building a cluster, you need to add features and instance name to use for building the cluster, I am not sure if it is feasible to use an existing instance and make it a primary cluster node?
SQL Server doesn't really DO active/active clustering. What is often CALLED active/active is 2 separate instances that are each Active/Passive, but hosted on 2 nodes of a Windows cluster. Each Instance is normally run on opposite nodes of the cluster so each node has 1 active instance and is the failover member for the other instance.
Instance Node A Node B
A -- > Active --> Passive
B --> Passive --> Active
As an old DEC VMS guy, I REALLY miss real active/active clustering.
January 30, 2015 at 11:03 am
Yes, that much I know and thank you for explaining it. I just still use the old terminology. However the question was not about how to setup the nodes. The question is can you make a standalone instance set as a primary cluster!? I believe you can't, but I am uncertain that is why I am asking.
January 30, 2015 at 11:53 am
lsalih (1/30/2015)
Yes, that much I know and thank you for explaining it. I just still use the old terminology. However the question was not about how to setup the nodes. The question is can you make a standalone instance set as a primary cluster!? I believe you can't, but I am uncertain that is why I am asking.
OK, so you're asking about merging 2 existing Windows servers into a single cluster...
It may be possible, but I wouldn't do it for production systems. You would probably be better off building a new failover cluster and then moving the instances to the new cluster.
January 30, 2015 at 12:22 pm
Brian Hibbert (1/30/2015)
lsalih (1/30/2015)
Yes, that much I know and thank you for explaining it. I just still use the old terminology. However the question was not about how to setup the nodes. The question is can you make a standalone instance set as a primary cluster!? I believe you can't, but I am uncertain that is why I am asking.OK, so you're asking about merging 2 existing Windows servers into a single cluster...
It may be possible, but I wouldn't do it for production systems. You would probably be better off building a new failover cluster and then moving the instances to the new cluster.
+1
Since the cluster name has to be distinct from the names of the nodes that participate in the cluster, not matter which way you slice it, you'd have to readjust names + who owns the storage + a whole bunch of other such items on an existing standalone install. Most of these activities would cause a fair amount of downtime on the affected physical server, and used to entail a fairly high likelihood of breakage.
You will be much better off standing up a new cluster, getting it running smoothly and then start moving DB's into the new cluster.
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Your lack of planning does not constitute an emergency on my part...unless you're my manager...or a director and above...or a really loud-spoken end-user..All right - what was my emergency again?
January 30, 2015 at 12:30 pm
Matt, thank you for your input, so I assume the answer is no for making an existing instance a primary node for the cluster. The primary cluster has to be build first, then add existing instances (nodes) to it. Correct?
January 30, 2015 at 5:20 pm
lsalih (1/30/2015)
Matt, thank you for your input, so I assume the answer is no for making an existing instance a primary node for the cluster. The primary cluster has to be build first, then add existing instances (nodes) to it. Correct?
We just don't do this in one fell swoop. Do it in parallel, make sure the new stuff works, then figure out what to do. As in:
Build up the cluster brand new, which involves getting the space lined up and allocated to the virtual cluster group. You can always build it with a single node in it for a while.
Build your instance within the cluster.
move/transfer all DB's into new instance (to include perms, users, etc... etc...)
TEST TEST TEST TEST TEST
Then once you know it's happy and working.... then perhaps you can de-allocate the space and re-purpose the existing server hardware to be nodes within the new cluster. Depending on how critical that server is - we've kept the single instance for 6 months before even considering a repurpose.
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Your lack of planning does not constitute an emergency on my part...unless you're my manager...or a director and above...or a really loud-spoken end-user..All right - what was my emergency again?
February 1, 2015 at 7:25 am
you cannot convert a standalone instance into a clustered instance, you will need to form a cluster on the 2 nodes and install new clustered instances and then migrate any objects into the new instance.
Do not be tempted to back and restore the standalone instance system databases into the new clustered instances either
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"Ya can't make an omelette without breaking just a few eggs" 😉
April 14, 2015 at 8:19 am
Perry -
I know this is an older post, but I want to ask about what if I setup a primary cluster, then add the two nodes to the cluster? When I present the disks to the primary, would there be a downtime? This project was set a side, but now I have to do it. I was thinking of downtime with either building a new cluster environment then migration the data or build a primary cluster and add the existing two nodes to it. Please advise.
April 15, 2015 at 3:34 am
Not sure what you mean with primary cluster, but initially you have to create a Windows cluster between the two nodes and run the validation checks against them with the shared disks available. Off hours, please, if the current instances are in production. 🙂 A lot of stuff is going to happen!
Not impossible you could run into some disk resource problems with existing disks you have to solve, if they're in the SAN as well. Make sure you know your LUNs and where they need to be. You have backups, right? 🙂
After the validations are OK and you have created the windows cluster, you can go ahead and install the clustered SQL instances you need. Allocate the resources for them with disks, IP etc.
Remember to test the clustered SQL instances so that they behave they way you want to _before_ migrating. Again, off hours. 🙂 Don't rush it!
April 15, 2015 at 6:47 am
Hi Jan -
Thank you for your feedback. If I first create windows cluster, then how I would add storage of the existing nodes to the cluster if the drives are owned by the two nodes. These two nodes are production servers, and that is what we want to make them clustered. Also, how much of downtime is involved? As you stated, off hours of course. Is it possible if you please briefly list the steps for presenting storage to the cluster. We are using SAN.
April 15, 2015 at 7:19 am
lsalih (4/14/2015)
Perry -I know this is an older post, but I want to ask about what if I setup a primary cluster, then add the two nodes to the cluster?
It makes no difference, the standalone instances cannot be converted to clustered.
lsalih (4/14/2015)
When I present the disks to the primary, would there be a downtime? This project was set a side, but now I have to do it. I was thinking of downtime with either building a new cluster environment then migration the data or build a primary cluster and add the existing two nodes to it. Please advise.
Build a new cluster and import any databases, users, jobs, etc
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"Ya can't make an omelette without breaking just a few eggs" 😉
April 15, 2015 at 7:23 am
Perry - To confirm, from what you are saying converting two standalone SQL servers to clustered environment is not an option since Cluster was not set at windows level to begin with, correct?
April 15, 2015 at 7:27 am
lsalih (4/15/2015)
Perry - To confirm, from what you are saying converting two standalone SQL servers to clustered environment is not an option since Cluster was not set at windows level to begin with, correct?
The standalone servers can be joined to a cluster, there's no issue with this.
Any standalone instances already installed on these nodes cannot be converted to clustered instances.
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"Ya can't make an omelette without breaking just a few eggs" 😉
April 15, 2015 at 7:29 am
Got it, thank you.
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