WesleyB's Blog : Windows Server 2008

SAP on SQL Server 2008 and Windows Server 2008

wesback — Fri, 06 Feb 2009 10:59:00 GMT

We are very proud to announce that SQL Server 2008 and Windows Server 2008 are now officially a supported solution for SAP.
More information can be found in this press release.

Some quick facts from our SAP portal site:

Over 65,000 SAP installations are on the Windows Server platform
Over 25,000 SAP installations are on SQL Server
Over 200 SAP customers have a productive database size of over 1TB and run on SQL Server
A joint Microsoft and SAP customer has a production database size of over 13TB and runs on SQL Server
A joint Microsoft and SAP customer is running SAP ERP with over 3,000 concurrent users on SQL Server
Another component of reducing cost - server consolidation - is addressed by Microsoft’s Virtualization solution that was recently certified by SAP

Running SQL Server 2008 in a Hyper-V Environment

wesback — Sat, 04 Oct 2008 16:15:00 GMT

This is probably one of the most frequently asked questions since we have released Hyper-V and SQL Server 2008.
I guess you all know we do support running SQL Server 2008 in a virtual environment ask explained here.

Like always there is no good answer to whether you should or should not run SQL Server in a virtualized environment, the only correct answers is: "it depends".

The nice people of SQLCAT have written up a whitepaper with guidance and best practices around SQL Server on Hyper-V.
Please make sure you read this whitepaper if you are thinking of running SQL Server on Hyper-V so you have a good understanding of the consequences of running in a virtualized environment.

*EDIT*
Make sure you read this post by PSS which contains new information about our support policy around virtualization.

Some I/O improvements in Windows Server 2008

wesback — Sat, 06 Sep 2008 18:38:00 GMT

I already posted this on my previous blog but the question comes up so often I decided to do a repost.

Windows Server 2008 offers a lot of new features that are very visible like Internet Information Server 7.0, a whole new virtualization model, Server Manager and many many more. But being a SQL Server person I am interested in other things that have been improved. These not so visible features are mostly I/O related since databases are a synonym for I/O. Also note that many (if not all) of these changes also apply to Windows Vista.

I/O Completion Port improvement

Before Windows Server 2008 a thread that issued an async I/O also executed the I/O completion task causing a context switch which is expensive. The I/O completion is now deferred until the thread pulls the I/O off the completion port preventing this context switch.

I/O prioritization

This is completely new to the OS, not only do your processes have a priority but also the I/O's that are triggered by these processes have their priority. This priority is based on the thread priority but can be set on the I/O itself too.

I/O Performance improvements

Using the GetQueuedCompletionStatusEx API call enables Windows to retrieve multiple completion port entries in one call.

Prior to Windows Server 2008 the Memory Manager and I/O system limited every I/O request internally to 64KB, larger requests were divided into multiple 64KB parts. This limit has been removed so every request can now be issued as a whole, meaning less transitions to kernel-mode to send the I/O to your storage device.

NUMA improvements

When working with SQL Server 2005 and later you will most likely encounter more and more NUMA enabled machines. In Windows Server 2008 more memory allocations procedures have been updated to be NUMA aware and I/O interrupts direct their completion to the node that initiated the I/O. An addition to the NUMA APIs also allows applications to specify the preferred node.

SMB2

According to the people who designed SMB2 this should help performance of large file copies over the network with factor 30 to 40. This will not really help your SQL Server performance but it will certainly get your backups to other servers faster.

For more information about kernel changes in Windows Server 2008 check out this great webcast by Mark Russinovich.

Windows Server 2008 Hyper-V

wesback — Thu, 26 Jun 2008 22:56:00 GMT

In case you did not notice yet, Hyper-V has RTM'ed!!!
More information can be found here and look here for more information about the performance of Hyper-V.

Did you know we are running lots of websites on Hyper-V already?