Availability Groups And VMs

John Martin looks at combining Availability Groups with a virtualized environment:

Much of the time there is a systems team and a DBA team, and when the DBAs need to build out a new set of SQL Servers, they request X number of virtual servers from the systems team. The servers are handed over and the DBA team works its magic, and then we have our Failover Cluster Instance or Availability Group High Availability solution. But, is it really Highly Available?

The reason I ask is twofold:

  • Which physical hosts are your Virtual Machines are located on?
  • Which data stores are your virtual disks are located in?

If the answer to either of these questions results in the same answer for any of your Virtual Machines in an Availability Group, or Failover Cluster Instance for that matter. Then you potentially have a massive flaw in your implementation that can affect availability.

The moral of the story is to communicate with the network administrators and SAN folks.

Related Posts

Dealing With Noisy Neighbors

Kevin Kline explains what Resource Governor does: There are lots of ways to manage noisy neighbors. For example, you could spin up additional instances of SQL Server on a single physical or virtual machine (VM), and then segregate the applications to a distinct instance. You could also follow the old adage of “one application, one […]

Read More

Creating Database Snapshots

David Fowler has a script which lets you create database snapshots easily: The procedure takes two parameters, @DatabaseList – a comma delimited string of database names, allows wildcards @ListOnly – 1- a list of affected databases will be displayed but snapshots aren’t created. 0- Snapshots are created automatically DEFAULT I’m a big fan of database […]

Read More

Categories

March 2016
MTWTFSS
« Feb Apr »
 123456
78910111213
14151617181920
21222324252627
28293031