SQL Server and Hyper-V Dynamic Memory

Lots of us are accidential DBAs.  In other words, we’re not DBAs officially, but SQL has made it’s way onto a large number of servers (or VMs) because of application requirements, e.g. System Center.

SQL is one of those applications that can be memory hungry and pretty damned hard to size.  That might just make it a perfect case for enabling Dynamic Memory on Hyper-V hosts, a feature of W2008 R2 SP1.

The SQLOS blog posted a series of 3 articles on Dynamic Memory and SQL.  I strongly recommend you read it … even if you don’t count yourself as a DBA.

  1.  SQL Server and Hyper-V Dynamic Memory – Part 1 – Understanding Dynamic Memory
  2.  SQL Server and Hyper-V Dynamic Memory Part 2 – Understanding how SQL deals with memory
  3.  SQL Server and Hyper-V Dynamic Memory Part 3 – Guidelines for configuring Dynamic Memory for SQL VMs

By the way, SQL 2005 and later Enterprise and Datacenter editions are required to take advantage of Dynamic Memory in SQL VMs.  This is because the lower editions (Express, Standard, Web and Workgroup) don’t support hot-add memory, something that was the domain of high end hardware prior to Dynamic Memory.  That’s unfortunate because those lower editions are likely what you have P2Vd from previous physical installs, and it isn’t uncommon to see SQL Web being deployed in a hosting environment (€11/month VS €260/month or more per CPU for a higher edition).

SQL vNext (codename Denali) is probably going to allow the Standard edition to support Dynamic Memory.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.