Dell PowerEdge R720xd Dell High Availability and Disaster Recovery Solutions U - Page 9

Dell High Availability and Disaster Recovery Solutions Using Microsoft SQL Server 2012 AlwaysOn Availability Groups The Dell H710 mini-integrated PowerEdge RAID Controller (PERC) card can be used efficiently to manage internal storage of the server. The H710P mini-card is designed for enhanced performance, increased reliability, and simplified management. For more details on the H710 PERC card refer dell.com/perc. In our test configuration, we used fully populated PowerEdge R720xd servers in the primary site and DR site. Two RAID-10 (10 disks for each) virtual disks are carved out from 20 disks to store the database files, and one RAID 1 virtual disk from the two drives for storing T-Log files. The last two hard drives might be used for Global Hot spares as shown in Figure 2. Figure 2. Simple AVG deployment on PE R720XD local storage Figure 2 shows the basic AlwaysOn Availability Group deployment with two replicas configured for Synchronous-Commit mode with automatic failover to provide High Availability. Another replica was configured with Asynchronous-Commit mode to provide DR capabilities to the AVG databases. Customers can add two more replica nodes (one in the primary and one in the secondary site) for further HA and DR capabilities. The quorum model and NodeWeight settings of the configuration should be based on the customer's specific application requirements. For more information on deploying AVGs, including prerequisites, restrictions, and recommendations for host computers, Windows Server Failover Clustering (WSFC) clusters, server instances, and availability groups refer http://msdn.microsoft.com/enus/library/ff878487.aspx. Major advantages and limitations of implementing AVG on non-shared storage Advantages:  A simple and cost effective solution for HA and DR  Perfectly suits SMB customer requirements  Quicker failover and failback operations because storage is locally attached  Reduced datacenter footprint and less power consumption when compared to shared storage solutions 9