Microsoft Exchange DAG
What an interesting afternoon reading and watching about the Microsoft Exchange Dag setup. I have spent a couple of hours learning on the CBT nuggets site what a DAG is and how you can now have LAG’s as well. Before I go any further, I highly recommend for any technician who wants to get high end correct knowledge to use CBT Nuggets. Its a brilliant site that gives you video access to why and how to set a particular technology up. Whether you are configuring an exchange network or Linux, its all there! Even test papers for some qualifications.
So lets get started. What is a DAG? I hear you cry, simply put DAG stands for Database Availability Groups. In simple terms, if an Exchange database get corrupts or you loose contact with it, you have the fail over to keep you ticking over. Now obviously there is a whole lot more to it than that but just to keep it simple it increases your redundancy. If you login to your Exchange administration panel and click on the left hand menu in Exchange 2013 you will see the menu “Servers”. Click on that and then you will see the headings appear along the top. Click on Database Availability Groups and in there you can start setting them up. Now like anything you are new to, do not just jump in and think it is straight forward. To a degree it is but there are several things to understand first and that is why it is worth following the CBT Nuggets videos and Microsoft Technet.
One of the features I really like that Microsoft have introduced are LAG databases. Now imagine the scenario, you are working happily away in your office doing normal IT support. You get an alarm go off or a user rings up saying they cant connect to their email. Well after closer inspection, you see the exchange database has become corrupt for one of many reasons. The LAG setup allows you to roll the database backwards to up to 14 days. How cool is that!!!