Great Christmas list! Too bad, I do not live in a perfect VM-world. Maybe I can get lucky in that new TV-show going national. It is called BINGO! Does the tooth fairy have an age restriction? I need to check the going price for a kidney on the auction block! I will be in the perfect world even if it requires my first born (no, I already allocated that for gasoline for 2008). I hear Aluminum cans are now going for around 65-cents. Have to go and volunteer for cleaning up a stretch of highway.

Herb5/11/2007 9:01:12 AM

I still feel scare about using SQL server on Virtualization platfrom in a production environment. Past SQL server document used to stress on its requirement on maintaining Write-Ahead Log algorithm, that said the log must be stored on disk (persistent storage) before its data buffer get flush. It even said that it use OS API which bypass any caching and issue I/O directly to the device.

In Virtualization scenario, the I/O command from guest OS actually is handled by corr. Virtualization software I/O layer. However, I see no document from either VM ware / MS, which claims their virtualization software can maintain the original I/O sequence. I even see a test report which found some extreme occasions that I/O on VM environment can even faster than its underlining physical barebone machine. I just think it is only possible if it twist the block size, using caching, or reorder the I/O command. Any of these measure may hamper the Database consistency, should abnormal shutdown occurs during system operation.

Can Microsoft SQL team really announce their supported Virtualization software, just like what they would announce for supported OS, which told us that they already prove that SQL server can work reliably (even in production environment) on such platform ?

Thanks for any advice to correct me on any misunderstanding on the issue.

Eric5/10/2007 9:17:15 PM

I am very interested in experiences on Virtualization of SQL Server in production environments. How about the difference in memory and i/o performance. It seems to me, you have more than a minimum disadvantage compared to performance on non virtualized SQL Server instances.

Gé5/10/2007 7:11:32 AM