re: SQL Server 2005 Multi-Site Clustering with Windows Server 2008

Rob_Carrol — Thu, 25 Jun 2009 21:55:23 GMT

Hi Reinaldo,

As you are only dealing with SQL Server technologies, Database Mirroring is a simpler solution to manage and much less expensive than SAN replication technologies. The main benefit of using a Windows geo-cluster would be that you are providing site-level tolerance for an entire SQL Server instance(s). Database Mirroring provides this at the database level only. If you had many databases that required this level of resilience, then that could give you additional administrative overhead managing logins, jobs, etc across both the instances.

Also, client applications have to be written in a way that supports automatic failover with Database Mirroring (http://msdn.microsoft.com/en-us/library/cc917713.aspx). Clustering is transparent to the client as they point towards a virtual IP address.

It really depends on your availability requirements and the amount of money you are prepared to spend to meet them. Database Mirroring provides a solution out of the box, so is always worth condsidering to see if it meets your disaster recovery needs before looking at specialist 3rd party SAN replication technologies.

Cheers,

Rob

re: SQL Server 2005 Multi-Site Clustering with Windows Server 2008

Reinaldo — Thu, 25 Jun 2009 19:14:47 GMT

Hi Rob, great article describing the features of Clustering. In reading the implementation, if using DBM (built in SQL Database Mirroring) other than the limit of 2 sites, it uses SQL technology only (1 stack). What are the advantages of using Windoes Cluster with Storage Replication?

My concern is when you have a failover, you have to deal with a minimum of 2 support teams. SQL DBA and Storage team. How easy is it to change the replication on the storage side?