This is the first part of the series “Installing SQL Server 2008/2008R2 Failover Cluster”.
Let me ask you something first! Have you ever been in the situation where you want to explore about your cluster, but your hands were tied because of the Live Production Server? Raise your Hands Up if “YES”. I can see lot of hands raised. Okay!Come back to your normal position before somebody sees you raising your hand, sitting in front of your computer ;-p.
Did you ever think that ” hey what happens if i do this on my cluster, what is that option, what is this option etc…” but again you couldn’t because of the real environment. I Agree we’ve POC(Proof Of Concepts) Servers for DBA’s team, but how much freedom do you really have to destroy the entire cluster?? Do you really think that you Boss will be Okay if you destroy the entire cluster in your LAB?? Most of the LAB environments I’ve seen will be a simple Stand Alone Server(s) where we can install and play with new SQL Server(s) and Service Packs and so on….But really they don’t fulfill our desire to explore and play with cluster and SAN!!
Don’t worry…in this Series I’m going to explain step by step installation right from creating your own Domain on a Domain Controller, Build your own SAN(Yeyyyyyyy! Exciting huh???), Build your Windows Servers and at last Installing SQL Server 2008 Failover Cluster 🙂
Before going any further, please read What a cluster can do?. So…by this time i assume you understood what a cluster can do from 20,000 miles distance!
Let me explain little bit further:
- Failover cluster is a combination of multiple Servers(Physical Nodes) all connected to a shared storage(SAN-Storage Area Network).
- If your Primary Node fails for some reason,the hot spare node(Active-Passive config) takes over the ownership of your application and all your operations continue to work seamlessly
- Failover Clustering provides high availability for your entire SQL Server Instance(Failover occurs as a Single unit) unlike Log shipping or Database Mirroring where they offer only Database level Failover.
- Your SQL Server Failover Cluster appears as a single computer to the clients connecting to you SQL Server.They don’t even know at what node SQL Server is running on.
- SQL Server offers Single Instance Clusters and Multi-Instance Clusters.
- Single Instance:Let us say, you’ve only one SQL Server Instance running at any given time on your cluster. It’ll be running either on your 1st node or 2nd node.(Active-Passive).
- Multi Instance: Let’s say you’ve 2 nodes running 2 Instances or even 4 Instances of SQL Server, Or let’s say you’ve 3 nodes where you’ve 2 Instances of SQL Server(Active-Active-Passive), the third node serving as a standby node ready to take ownership in an event of any failure of Node1 or Node2.
Things to Know:
- Failover Clustering is an Enterprise edition feature. So, You can create a FOC only on Windows Server Enterprise or above(Windows Server Data Center Edition).
- SQL Server 2008 Enterprise on Windows Server Enterprise/Data center supports upto 16 Physical Nodes and 50 Instances of SQL Servers 🙂
- You can do SQL Server Cluster installation with SQL Standard edition too(But remember Windows needs to be minimum on enterprise edition)…but it only support upto 2 physical Nodes and can be scaled upto 16 Instances of SQL Server!!(which is never a good solution to go upto 16 Instances on Just 2 Nodes)
- SSIS/SSRS are not cluster aware by default.(You can imagine SSRS as a Web Service where you really don’t need to be as a fail over cluster service. Typically it goes with scaled out deployment on NLB Clustering).
- There are few tricks where we can cluster SSIS, but it is not recommended by Microsoft to cluster your SSIS installation.
- Minimum 2 windows servers(enterprise edition) besides your domain controller.
- All the participating Hardware and drives should be certified by microsoft.
- minimum two NIC are needed per server. Netbios should be disabled on the network cards associated with HeartBeat(Private network).
- Shared Storage(SAN) is needed. Again PS, this should be microsoft certified.
- Ensure that disks have same drive letter mappings on all the physical nodes participating in clustering.
- Windows Server Failover Clustering Feature and Application role should be added on Each node manually participating in SQL clustering.