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sql-servercluster-computingfailoverclustersan

Does each instance of SQL Server on a cluster require its own LUN?

I'm setting up a Misc SQL Cluster (Windows 2008/SQL 2005 & 2008) that will be active/active and have about a dozen SQL instances on it. From the documentation I've read, I can't tell if each SQL instance will need its own LUN, or if I can have a single, really big LUN created, and then create a dozen different partitions on that LUN (one for each SQL instance).

In either case, the physical disk layout on the SAN won't change, so it really doesn't matter from a performance standpoint which one I choose (assuming I can choose either). I just want to know if the partition method works, or if each instance needs to own its own LUN to handle the failover properly.

Solution

  • Each instance will need separate disks/LUNs. They will be "owned" by the active node and are a dependent resource.

    If you think about it, how can 2 SQL Server instances share a drive? It's a conflict.

    Since Windows 2003 you can use NTFS mount points, that is mount a LUN in an empoty folder in a drive. I've not tried it myself though.

    Edit: some nice pictures here "How do Cluster Shared Volumes work"