Smart Array 5i Plus Controller and Battery Backed Write Cache Enabler

[Steven Hellyer]

Does anyone know if the Smart Array 5i Plus Controller is specifically designed for use with databases?

According to Microsoft you run the risk of database corruption if you use a write-caching disk controller that is not designed for databases.

This is because SQL Server relies on the Windows OS to notify it when an I/O operation has completed. If anyone has any insight on this I would be very grateful.

Thanks,

Steven

[Bob Bell_1]

Although I do not know if this specific controller is "designed" for specific db use, Most descent controllers will allow you to set the write-through and write-back cache policies to suite your needs and comfort levels. I am fairly certain this is true about the SA 5i controller too..

[Bob Bell_1]

Just a note: it would be that the controller signals as a successful (i/o completion) "write" to the cache or the disk that is difference in the write-back (cache) and write-through (disk)..

[Glenn Weavind_1]

I think you'll find that all of the HP/Compaq write-cacheing array controllers meet your requirements. The only possible issue is that one thread of your DB writes to the DB - and the array controller caches it: if another thread now attempts to read the same record information, a well designed array controller will fulfill the request from the recently updated cache (which give the DB thread the latest, correct informtion). A poorly designed array controller would supply information from HDD, and supply out-of-date information. Such an array controller would rapidly become notorious, and stop selling.
I think you'll find that the Microsoft 'advice' is teaching granny to suck eggs.