SAN Considerations for SQL Server
Before you rush out and purchase a SAN or two for your SQL Server environments, there are some considerations to keep in mind when using SANs with SQL Server.
One of the reasons SANs can offer superior performance to locally attached storage is they typically are configured with a significant amount of cache space. This is normally a good thing. However, because the SAN provides storage services to multiple servers, the available cache space is shared as well. If there is significant activity against the SAN, there can be extensive cache turnover. This means that the large cache space may not always be available to SQL Server, so some of the performance gains provided by the large cache are ...