Hardware Redundancy and Failover

This section provides basic information that will help you determine how to connect a host to the RAID controller modules in a RAID enclosure in order to achieve redundancy and failover.

NOTE: The best practice for ensuring data access is to avoid a configuration with a single point of failure. A single point of failure is any component or path that is not duplicated (redundant) or whose failure can cause loss of data access.

Redundancy and Non-Redundancy

Redundancy means that a storage array has duplicate components, or alternate ways to provide essential services. This redundancy ensures access to the virtual disks in case of a failure of a single component.

In a typical RAID configuration, most of the components are redundant; however, the configuration itself might not be fully redundant. For example, there might be components whose individual failure would cause loss of access to the virtual disks. In a fully redundant storage array, all components must be duplicated. In addition, the storage array must be configured in such a way as to ensure that duplicate components can be accessed in case of a failure. The manner in which the storage array is cabled is an essential component of creating a successfully configured redundant storage array.

Multi-Path Software

Multi-path software (also referred to as the failover driver) is software resident on the host server that provides management of the redundant data path between the server and the RAID enclosure. For the multi-path software to correctly manage a redundant path, the configuration must provide for redundant HBAs and cabling.

The multi-path software identifies the existence of multiple paths to a virtual disk and establishes a preferred path to that disk. If any component in the preferred path fails, the multi-path software automatically re-routes I/O requests to the alternate path so that the storage array continues to operate without interruption.

NOTE: Multi-path software is included with MD Storage Manager.

Preferred and Alternate Controllers and Paths

A preferred controller is a RAID controller module designated as the owner of a virtual disk or disk group. The preferred controller is automatically selected by MD Storage Manager when a virtual disk is created. You can change the preferred RAID controller module owner of a virtual disk after it is created.

Ownership of a virtual disk is moved from the preferred controller to the second controller (also called the alternate controller) when the preferred controller is:

•Physically removed

•Updating firmware

•Involved in a fatal event that caused failover over to the alternate controller

Using Your RAID Enclosure

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Dell MD3000 owner manual Hardware Redundancy and Failover, Redundancy and Non-Redundancy, Multi-Path Software
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MD3000 specifications

The Dell MD3000 is a renowned storage area network (SAN) solution recognized for its flexibility, scalability, and high performance. Designed to meet the demands of small to medium-sized businesses (SMBs) and enterprise environments, the MD3000 offers a plethora of features that enhance data management and storage capabilities.

One of the standout features of the MD3000 is its modular design. This allows users to start with a basic configuration and expand their storage capacity as their needs grow. The system can support up to 30 drives, including both SATA and SAS drives, giving users the ability to optimize cost and performance based on their specific requirements. With support for a diverse range of drive types, the MD3000 ensures that businesses can implement a storage solution that aligns perfectly with their performance and budgetary needs.

The MD3000 leverages advanced technologies to deliver exceptional performance and reliability. It is equipped with Intelligent Disk Pools that optimize the allocation of data across drives, ensuring improved access speeds and overall system efficiency. This dynamic management of data not only enhances performance but also extends the lifespan of the storage devices.

Data protection is another critical component of the MD3000. The system features various RAID configurations, allowing users to choose the level of redundancy that suits their operational requirements. Additionally, robust snapshot capabilities help businesses create point-in-time copies of their data, enabling quick recovery in case of data loss or corruption.

Connectivity options are abundant with the MD3000. It supports both iSCSI and Fibre Channel, providing users the flexibility to integrate it seamlessly into existing network infrastructures. This adaptability makes it an attractive option for organizations looking to modernize their storage systems without overhauling their entire architecture.

Furthermore, the MD3000 is equipped with a user-friendly management interface. The GUI enables quick provisioning and monitoring of storage resources while providing insightful analytics and alerts, allowing IT teams to maintain optimal performance with ease.

In summary, the Dell MD3000 is a highly versatile and efficient storage solution that meets diverse organizational needs. Its scalable architecture, advanced features, and strong support for data protection and management make it an ideal choice for businesses aiming to enhance their storage capabilities while ensuring reliability and performance. Whether for virtualization, database management, or general storage needs, the MD3000 stands out as an excellent investment in enterprise storage technology.
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