Dell POWEREDGE R720 - Manual (Page 14)

Microsoft SQL Server 2012 Fast Track Reference Configurations using PowerEdge R720 and PowerVault MD3620i
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Storage system configuration
The Fast Track Reference Architecture guidelines define three primary layers of storage configuration:
• Physical disk array (RAID Groups for Data and Logs)
• Operating system volume assignment (LUN)
• Databases: User, System Temp, Log
On each storage array, for the primary user and system temp database files:
• Four RAID 5 disk groups were created, each consisting of eleven disks (two disk groups each from
the base and the expansion enclosure)
• One virtual disk (LUN) was created out of each disk group. These LUNs were evenly distributed
across the storage controllers.
Therefore, there were four LUNs (virtual disks) for the primary user data. Each storage controller was
assigned two of the LUNs.
For the primary user and system temp database transaction logs, one RAID1 disk group was created of 2
disks. This RAID group was dedicated to host the database transaction log files.
The remaining 2 disks on the storage array were assigned as the storage hot spares (global).
Figure 10 shows the pictorial representation of the LUN layout in the storage array.
Storage LUN layout Figure 10.