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Appendix: RAID Description

RAID is a group of independent physical disks that provides high performance by increasing the number of disks used for saving and accessing data.

CAUTION: In the event of a physical disk failure, a RAID 0 virtual disk fails, resulting in data loss.

A RAID disk subsystem offers the following benefits:

•Improved I/O performance and data availability.

•Improved data throughput because several disks are accessed simultaneously. The physical disk group appears either as a single storage unit or multiple logical units to the host system.

•Improved data storage availability and fault tolerance. Data loss caused by a physical disk failure can be recovered by rebuilding missing data from the remaining physical disks containing data or parity.

Summary Of RAID Levels

NOTE: PERC H710, H710P and H810 cards support all RAID levels listed below. PERC H310 supports RAID 5 with limited performance and does not support RAID 6 and RAID 60.

•RAID 0 uses disk striping to provide high data throughput, especially for large files in an environment that requires no data redundancy.

•RAID 1 uses disk mirroring so that data written to one physical disk is simultaneously written to another physical disk. RAID 1 is good for small databases or other applications that require small capacity and complete data redundancy.

•RAID 5 uses disk striping and parity data across all physical disks (distributed parity) to provide high data throughput and data redundancy, especially for small random access.

•RAID 6 is an extension of RAID 5 and uses an additional parity block. RAID 6 uses block-level striping with two parity blocks distributed across all member disks. RAID 6 provides protection against double disk failures, and failures while a single disk is rebuilding. If you are using only one array, deploying RAID 6 is more effective than deploying a hot spare disk.

•RAID 10 is a combination of RAID 0 and RAID 1, uses disk striping across mirrored disks. It provides high data throughput and complete data redundancy. RAID 10 can support up to eight spans, and up to 32 physical disks per span.

•RAID 50 is a combination of RAID 0 and RAID 5 where a RAID 0 array is striped across RAID 5 elements. RAID 50 requires at least six disks.

•RAID 60 is a combination of RAID 0 and RAID 6 where a RAID 0 array is striped across RAID 6 elements. RAID 60 requires at least eight disks.

RAID Terminology

Disk Striping

Disk striping allows you to write data across multiple physical disks instead of just one physical disk. Disk striping involves partitioning each physical disk storage space in stripes of the following sizes: 64 KB, 128 KB, 256 KB, 512 KB, and 1024 KB. The stripes are interleaved in a repeated sequential manner. The part of the stripe on a single physical disk is called a stripe element.

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Dell H310, H710P, H810 manual Appendix RAID Description, Summary Of RAID Levels, RAID Terminology, Disk Striping
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H310, H710, H710P, H810 specifications

Dell offers a range of storage controller technologies, notably the H810, H710, H710P, and H310, which cater to different enterprise needs. These controllers are designed to support various storage configurations, enhancing overall system performance and reliability.

The Dell H810 is a high-performance PCIe 3.0 RAID controller that supports up to eight internal drives and is particularly suited for demanding workloads. It features advanced RAID levels including RAID 0, 1, 5, 6, 10, 50, and 60, providing flexibility for various data protection strategies. The H810 also supports up to 32TB of storage capacity, making it suitable for environments that require substantial data management capabilities.

The H710 is another powerful RAID controller, widely recognized for its balance of performance and cost-efficiency. It features 1GB of cache memory, which aids in accelerating read and write operations. The H710 supports the same RAID levels as the H810 and allows for up to 512MB of non-volatile memory. This ensures data integrity even in the event of a power failure, making it reliable for critical applications.

The H710P is an enhanced version of the H710, with a significant upgrade in its cache capabilities. It offers 2GB of battery-backed cache memory, further enhancing data processing speeds and improving responsiveness. The H710P is ideal for intensive workloads and virtualization, where rapid access to data is essential. This controller also includes features such as RAID storage pooling, intelligent data tiering, and support for multiple virtual disks.

Finally, the H310 is a cost-effective option for small to medium-sized businesses or those with less demanding storage requirements. It offers similar RAID support as the higher-end controllers but operates with a simpler architecture. The H310 features 512MB of cache, providing sufficient performance for regular workloads without the additional complexities of more advanced controllers.

In summary, Dell's H810, H710, H710P, and H310 storage controllers each serve distinct purposes, providing various features, technologies, and performance characteristics tailored to different business needs. From high-capacity storage solutions to user-friendly setups, Dell’s offerings ensure that organizations can efficiently manage their data storage requirements.
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