SQL, SAN's and direct block level access??? | SQL Server Performance Forums

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SQL, SAN’s and direct block level access???

Hi I have a SQL database that references image files stored on a windows NTFS file system by use of a unc path, currently a 1TB NAS unit. My storage requirement is about to explode and I will be implementing an EVA SAN solution in the very near future, aprox 16 to 24TB. Can SQL reference files stored at the block level? If not I have to use a NAS header gateway to create a virtual NTFS file system for my file storage. This presents me with the problem that clustered NAS boxes cannot use dynamic disks and so I will be restricted to 2TB basic disks. I have tried to ask Microsoft if Storage Server 2003 gets around this restriction but they don’t seem to be able to give me an answer, passing me instead to the NAS re-seller as storage server is an oem product!!! Another theoretical option would be to implement a Netware 6.5 server cluster and create a massive Netware partition on the SAN, using unc paths in the db to reference files on the NW volume…not sure if I can do this either? At the moment my software will not easily distribute uploaded files across multiple $shares hence the reason for partitions greater than 2TB in size. All thoughts/answers are very greatly appreciated. Mike Halsey
Those are very big figures you are talking about. Are you sure you want to keep all these files on a single volume? This must be a maintenance headache! If your application is not good at handling multiple paths I would look to use Microsoft’s Distributed File System (DFS). It’s actually quite good with large volumes (unless you try using replication). I’m afarid I can’t offer much more advice… Simon
Yep, they sure are big numbers…It may be that we have to rewrite our software to cope with using smaller sized disk chunks but that will give us a lot more problems than just working with one big space. As for DFS…I could do the same with Novell, ie; create one Logical Partition which spans multiple disks, however, this is not recommended by Novell for several reasons, all of which would apply equally to MS DFS, namely Disaster Recovery. There must be somebody out there who uses volume sizes greater than 2TB. Cheers Mike