•Physically removed

•Updating firmware

•Involved in an event that caused failover to the alternate controller

Paths used by the preferred RAID controller module to access either the disks or the host server are called the preferred paths; redundant paths are called the alternate paths. If a failure causes the preferred path to become inaccessible, the storage array automatically uses the alternate path to access data, when this occurs the enclosure status LED blinks amber.

Virtual Disk Ownership

MDSM can be used to automatically build and view virtual disks. It uses optimal settings to stripe the disk group. Virtual disks are assigned to alternating RAID controller modules when they are created. This default assignation provides a simple means for load balancing the workload of the RAID controller modules.

Ownership can later be modified to balance workload according to actual usage. If virtual disk ownership is not manually balanced, it is possible for one controller to have the majority of the work, while the other controller is idle. Limit the number of virtual disks in a disk group. If multiple virtual disks are in a disk group, consider:

•The impact each virtual disk has on other virtual disks in the same disk group.

•The patterns of usage for each virtual disk.

•Different virtual disks have higher usage at different times of day.

Load Balancing

A load balance policy is used to determine which path is used to process I/O. Multiple options for setting the load balance policies lets you optimize I/O performance when mixed host interfaces are configured.

You can choose one of these load balance policies to optimize I/O performance:

•Round robin with subset—The round robin with subset I/O load balance policy routes I/O requests, in rotation, to each available data path to the RAID controller module that owns the virtual disks. This policy treats all

Planning: MD3200i Series Storage Array Terms and Concepts

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Dell MD3200i, MD3220i owner manual Load Balancing, Virtual Disk Ownership
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MD3200i, MD3220i specifications

The Dell MD3220i and MD3200i are part of Dell's extensive line of modular storage solutions, designed to support organizations in optimizing their data management and scalability requirements. These models offer reliable performance and flexible features, making them suitable for various workloads including virtualization, cloud storage, and disaster recovery.

One of the standout features of the MD3220i and MD3200i is their support for iSCSI storage networking. By utilizing the Internet Small Computer Systems Interface (iSCSI) protocol, these systems provide organizations with a cost-effective way to connect their storage over existing network infrastructure, enabling efficient data transfers and management.

Both models are equipped with dual controllers that ensure high availability and failover capabilities, which are crucial for meeting uptime requirements in mission-critical environments. The dual controllers also facilitate load balancing and increase overall system performance, as they allow multiple paths to the storage, enhancing I/O performance.

Scalability is another key characteristic of the MD3220i and MD3200i. These storage arrays can be expanded to meet growing storage demands, supporting up to 240TB of raw capacity with up to 16 additional expansion enclosures. This flexibility allows organizations to start with a smaller configuration and grow their storage capabilities without a complete overhaul of the existing infrastructure.

The units also support multiple disk types, including traditional spinning disks, solid-state drives (SSDs), and a combination of both. This versatility enables users to tailor storage configurations to their specific performance and budgetary needs. Furthermore, the systems feature advanced data management technologies such as snapshots and remote replication, providing essential tools for data protection.

With their ease of management, the MD3220i and MD3200i are designed for straightforward configuration and operation. The intuitive management interfaces allow IT professionals to monitor performance, configure storage, and manage data effectively, ensuring businesses can maintain optimal system availability.

In summary, the Dell MD3220i and MD3200i are robust, scalable, and versatile storage solutions that cater to diverse organizational needs. Their integrated technologies, such as iSCSI support, dual controller architecture, and advanced data management features, make them an ideal choice for modern data centers looking to enhance storage capabilities while ensuring reliability and performance.
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