Hi Sergey,

Our environement is compose of 3 SQL server:
One production, one Staging server, one Development server.
We also have a SAN for storage.

The production server uses a HBA bus to connect to the SAN meaning that it boot from the SAN and SQL data reside on the SAN like a local drive of the machine.


HBA busses are very expensive and we bought them only for production server.

So for Staging and Dev server we have two machine with their own hard drive (without HBA busses), They boot locally on their hard drive and they run SQL server. My problem with this configuration was that SQL didn't permit me to put SQL data on a map drive or to use a UNC path. So with the flag discuss in the article I can put my SQL data from my Staging and Dev computer on a Map drive that reside on SAN.

This way my SQL Production server is fully integrate to the SAN and my two other SQL server (Dev and Stage) are configure half and half, they boot from a local hard drive and the use the SAN to store SQL data. This way I can spare 2 HBA busses and still use the SAN as a storage. My backup schema is simplified and my SQL Data is protect by the SAN with redunduncy and fault tolerance.

The only draw back is that the DEV and Staging SQL server might not recover correctly from a machine crash because the SQL only control disk caching on local drive. In my case only the production server need that kind of protection.



>Hi Luc,
>
>The article you refered to is related to NAS not SAN. I don't think it's a good idea to store SQL Server data files on NAS because of performance and reliability issues.
>
>>Thanks Sergey
>>
>>I had to use one of my MSDN issue to get this one...
>>
>>This behavior is expected. Trace flag 1807 bypasses the check and allows you to configure SQL Server with network-based database files. SQL Server, and most other enterprise database systems, employ a transaction log and associated recovery logic to ensure transactional database consistency in the event of a system failure or an unmanaged shut down. These recovery protocols rely on the ability to write directly to the disk media so that when an operating system input/output (I/O) write request returns to the database manager, the recovery system is guaranteed that the write is actually complete or that the completion of the write can be guaranteed. Any failure by any software or hardware component to honor this protocol can result in a partial or total data loss or corruption in the event of a system failure. For more details about these aspects of logging and recovery protocols in SQL Server, refer to the following article in the Microsoft
>>
>>Microsoft Knowledge Base Article - mskb #304261
>>
>>
>>So I've put -T1807 in the SQL server startup parameter.
>>
>>
>>
>>>>I wish to install our SQL server on machine linked on the LAN but I want the Data files (Databases) to reside on the SAN (Storage Area Network).
>>>>
>>>>Can it be done and how?
>>>
>>>Luc,
>>>
>>>Maybe this could help
>>>
>>>- http://www.sql-server-performance.com/ew_san.asp
>>>- http://activeanswers.compaq.com/ActiveAnswers/Render/1,1027,5175-6-100-225-1,00.htm
>>>- http://www.dell.com/us/en/esg/topics/products_sql_papers_pedge_software_microsoft_sql_papers.htm