SQL Server High Availability and Disaster Recovery with Dell EMC SC Series Abstract This paper discusses options available with Dell EMC™ SC Series storage and Microsoft® SQL Server® and how they can be used to architect the right solution for even the most challenging environments.
Revisions Revisions Date Description 11/14/2011 Initial release 07/26/2012 Technical Review 10/5/2012 Updated for Enterprise Manager 6.2 December 2016 Complete document update November 2018 Format updates Acknowledgements Updated by: Doug Bernhardt The information in this publication is provided “as is.” Dell Inc.
Table of contents Table of contents Revisions.............................................................................................................................................................................2 Acknowledgements .............................................................................................................................................................2 Executive summary..................................................................................................
Executive summary Executive summary Microsoft® SQL Server® is used to host databases that can have a wide variety of high availability (HA) and disaster recovery (DR) requirements. Both Microsoft SQL Server and Dell EMC™ SC Series storage arrays have a number of capabilities that can be used to design solutions to fit these requirements.
Overview of Dell EMC SC Series tools for HA/DR 1 Overview of Dell EMC SC Series tools for HA/DR Several types of events can have an effect on the availability of SQL Server databases and the applications that use them. These events range from unplanned events, such as natural disasters that may impact an entire data center, to planned events such as hardware or software upgrades.
Overview of Dell EMC SC Series tools for HA/DR 1.3 Live Migration Occasionally, there is a need to migrate storage between SC Series arrays for hardware refreshes, change of location, or other reasons. Typically, this would involve replicating the database to new volumes, using either SQL Server log shipping or database mirroring, and then taking a brief outage as the database on the source volumes is swapped out for the database copy on the new volumes.
Overview of Dell EMC SC Series tools for HA/DR Note: The term replication in this document refers to SC Series replication. While Microsoft SQL Server does offer various types of data replication, they are not typically used to satisfy high availability requirements and therefore not discussed in this document. 1.5.1 Asynchronous replication Dell EMC SC Series asynchronous replication offers a great amount of flexibility.
Overview of Dell EMC SC Series tools for HA/DR reports on the amount of data that would be replicated given the selected options. This information can be used to make better replication architecture decisions. If you are satisfied with the simulated replication, it can be converted into an actual replication. 1.6 Synchronous Live Volume w/Auto Failover Always On Failover Cluster Instances (FCIs) are one of the key technologies recommended by Microsoft for providing High Availability for SQL Server.
Comparing Microsoft SQL Server and SC Series availability features 2 Comparing Microsoft SQL Server and SC Series availability features 2.1 High availability features When selecting an architecture for high availability, it may be beneficial to compare SQL Server features to SC Series array features. High Availability Solutions (SQL Server) recommended by Microsoft include Always On Failover Cluster Instances (discussed above), Always On Availability Groups and log shipping.
Comparing Microsoft SQL Server and SC Series availability features Always On Availability Groups in synchronous mode operates similar to SC Series Synchronous Replication in High Availability mode. Data is replicated synchronously. In the event the connection to the secondary exceeds the timeout threshold, the primary continues to accept writes, without replicating to the secondary, until the issue is resolved.
Comparing Microsoft SQL Server and SC Series availability features database types, other applications, etc. that require a protection solution as well. Data protection at the storage layer provides broad capabilities and recovery features of the SC Series arrays can be used for a wide range of products and data protection needs. 2.2.
Preparing SQL Server for SC Series Replication 3 Preparing SQL Server for SC Series Replication When using SC Series replication for data protection, in addition to choosing the proper type of replication there are other considerations that should be taken into account. Paying careful attention to the following items will assist in performance, efficiency, and recoverability of the replication solution. 3.1.
Preparing SQL Server for SC Series Replication database tuning offer the largest gains in terms of performance and scalability not only for replication but for the entire system and the importance can’t be emphasized enough. 3.1.6 Testing Testing an HA/DR architecture is critical to ensure that if an issue arises the system performs as expected. Often this is difficult to do and requires careful scheduling and coordination to perform an actual failover to perform verification.
Additional resources A Additional resources A.1 Technical support and resources Dell.com/support is focused on meeting customer needs with proven services and support. Storage Solutions Technical Documents provide expertise that helps to ensure customer success on Dell EMC Storage platforms. A.
