Reference Architecture

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It is important to include space for the guest operating system memory cache, snapshots, and VMware
configuration files when sizing these volumes. Additionally, you can configure thin-provisioned volumes
to grow on demand only when additional storage is needed for those volumes. Thin provisioning can
increase the efficiency of storage utilization.
With each volume created and presented to the servers, additional iSCSI sessions are initiated. When
planning the solution, it is important to understand that group and pool limits exist for the number of
simultaneous iSCSI sessions that can created.
For more information, refer to the current EqualLogic Firmware (FW) Release Notes available at the
EqualLogic Support site.
8.4 Drive Types and Automated Tiered Storage
Dell EqualLogic PS6110 arrays, with the 10Gb dual-controller configuration, provide high bandwidth for
data flows. This bandwidth is complemented with a large variety of drives in multiple speeds and sizes,
including 10K RPM and 15K RPM SAS drives, 7.2K RPM NL-SAS drives and solid-state disks. The reference
architecture presented in this document shows EqualLogic PS6110X arrays with 24 x 10K RPM SAS drives
in each array. The disk and array type should be selected by carefully considering the workload
requirements. Active System 800v supports a maximum of 8 x PS6110 arrays.
EqualLogic PS arrays provide IT organizations numerous techniques for storage tiering as a standard
part of their all-inclusive feature set. These techniques extend the automation at the core of the PS
Series design philosophy, while allowing broad customization of storage tiers to suit a wide range of
business and organizational requirements.
8.5 Multipath Configuration
The Dell EqualLogic PS Series storage array supports multiple iSCSI SAN connections for performance
and reliability. Multi-Path I/O (MPIO) provides multiple paths from servers to storage, delivering fault
tolerance, high availability, and improved performance. Active System 800v uses EqualLogic Multipath
Extension Module (MEM) for VMware vSphere to enable MPIO for the iSCSI storage.
EqualLogic MEM offers:
 Ease of installation and iSCSI configuration in ESXi servers
 Increased bandwidth
 Reduced network latency
 Automatic load balancing across multiple active paths
 Automatic connection management
 Automatic failure detection and failover
 Multiple connections to a single iSCSI target
Once installed, the EqualLogic MEM will automatically create iSCSI sessions to each member that a
volume spans. As the storage environment changes, the MEM will respond by automatically adding or
removing iSCSI sessions as needed.