PERC

RAID Controller & PERC

A RAID (Redundant Array of Independent Disks) controller is a hardware component that manages the configuration of multiple hard drives or SSDs in a RAID array. It allows the drives to work together, either for performance optimization or redundancy, ensuring data integrity and availability. A RAID controller typically connects to the motherboard via a PCIe slot, with some advanced controllers offering dedicated ports for connecting hard drives. RAID controllers are essential for businesses and professionals who require high availability, speed, and data redundancy, especially when dealing with large data storage setups.

What is PERC?

The PowerEdge RAID Controller (PERC) is Dell's branded RAID controller used in its PowerEdge server line. These controllers are known for offering reliable and scalable RAID performance for enterprise-level data storage needs. PERC controllers are designed to offer a wide range of RAID configurations, including RAID 0, RAID 1, RAID 5, RAID 10, and RAID 50, which provide different combinations of redundancy and performance. The versatility and performance of PERC controllers make them an excellent choice for data-driven businesses that rely on high-volume storage.

PERC Series Overview

The PERC series consists of several generations, each offering different levels of performance, reliability, and functionality. Whether you're building a data center or upgrading your server's storage capabilities, understanding the different PERC series options will help you make an informed decision.

PERC H330

The PERC H330 is an entry-level RAID controller designed to offer affordable RAID configurations for PowerEdge servers. It provides basic RAID functionality, including support for RAID 0, 1, 5, and 10. While it is not as feature-rich as some of the higher-end models, it is perfect for small to medium-sized businesses looking to manage data across multiple drives without the need for high-end capabilities.

PERC H730 & H730P

The PERC H730 and H730P are mid-range controllers that deliver more advanced features compared to the H330. With these models, you gain access to greater levels of data protection and performance, such as the ability to support RAID 5, RAID 6, RAID 10, and even RAID 50. Additionally, the H730P includes dedicated cache memory, offering improved write performance and fault tolerance.

PERC H840

The PERC H840 is designed for high-performance environments, offering even more advanced RAID management features. This model supports both internal and external drive configurations, making it ideal for businesses that need to manage large-scale storage setups. The H840 offers enhanced data protection features, including an advanced RAID algorithm that ensures minimal risk of data loss during drive failures.

Key Features

PowerEdge RAID controllers are known for their exceptional performance and data security. Here are some of the key features that set PERC apart from other RAID controllers:

Advanced Data Protection

PERC controllers offer advanced data protection by supporting various RAID levels such as RAID 1 (mirroring), RAID 5 (striping with parity), and RAID 6 (double parity). These RAID configurations ensure that data is protected in case of drive failure, minimizing downtime and ensuring that your server can continue running smoothly.

Cache Management

Many PERC models, especially those in the H7xx series, come with built-in cache memory. This cache helps to improve write performance, as the data is first written to the cache before being committed to the disk. This improves overall system responsiveness and reduces latency during high-traffic workloads.

Battery-Backed Cache (BBU)

Some higher-end PERC models come with a Battery-Backed Cache (BBU). This feature ensures that the data in the cache is not lost during power outages, improving data integrity and system stability. The BBU stores cached data temporarily, allowing it to be written to disk once power is restored.

RAID Levels Supported by PERC Controllers

Understanding the RAID levels that PERC controllers support is crucial when choosing the right solution for your storage needs. Different RAID levels offer varying benefits in terms of performance, redundancy, and cost. Below are the most commonly supported RAID levels:

RAID 0: Striping

RAID 0 is the simplest RAID configuration, where data is split evenly across two or more drives. It offers excellent performance because data is read and written simultaneously to multiple drives. However, RAID 0 provides no data redundancy, meaning that if one drive fails, all data is lost.

RAID 1: Mirroring

RAID 1 mirrors the data across two drives, providing redundancy in case of drive failure. If one drive fails, the system continues to operate without any data loss, as the data is identical on both drives. RAID 1 offers a good balance between redundancy and performance, though it sacrifices storage capacity due to mirroring.

RAID 5: Striping with Parity

RAID 5 combines the performance benefits of RAID 0 with the redundancy of parity. Data is striped across multiple drives, and parity information is distributed across all drives. In the event of a single drive failure, the missing data can be rebuilt from the parity information, ensuring minimal downtime. RAID 5 is one of the most popular RAID configurations for enterprise servers.

RAID 10: Mirrored Striping

RAID 10 combines the features of RAID 0 and RAID 1, offering both performance and redundancy. Data is striped across multiple drives and mirrored, ensuring that even if one drive in the mirror pair fails, the data can still be accessed from the other drive. RAID 10 offers high performance and redundancy, but it requires at least four drives and sacrifices storage space due to mirroring.

RAID 50: Striping with Double Parity

RAID 50 combines the benefits of RAID 5 and RAID 0. It provides the redundancy and fault tolerance of RAID 5 but also delivers better performance by striping data across multiple RAID 5 sets. This makes RAID 50 an excellent option for high-performance applications that require large amounts of storage and data protection.

Benefits

When it comes to managing data storage for your PowerEdge server, PERC controllers offer several distinct advantages. These benefits include enhanced data protection, performance, scalability, and more. Below are some of the main advantages of using PERC RAID controllers in your server setup:

High Availability

PERC controllers help ensure high availability of data by offering redundancy features such as RAID 1, RAID 5, and RAID 6. In the event of a drive failure, the RAID configuration allows the server to continue operating without data loss or significant downtime, which is critical for mission-critical applications.

Improved Performance

With advanced RAID levels and built-in caching mechanisms, PERC controllers significantly improve the overall performance of your server storage. RAID 0, for example, boosts performance by enabling simultaneous reading and writing of data across multiple drives. This is particularly beneficial for environments with high I/O demands, such as databases and virtualized applications.

Scalability

PERC controllers are highly scalable, offering support for large numbers of drives and multiple RAID arrays. This scalability ensures that your server infrastructure can grow as your business or data storage needs expand, allowing for easy addition of drives without downtime or system disruption.

Comprehensive Management Tools

For ease of management and monitoring, Dell offers comprehensive software tools for managing PERC controllers. These tools allow administrators to configure RAID arrays, monitor the health of drives, and receive alerts for potential failures. With these management tools, it's easier to keep your storage systems running smoothly and prevent issues before they arise.

Choosing the Right PERC Controller for Your Needs

Choosing the correct PERC controller depends on your server's workload and storage requirements. If your business handles a large volume of data or critical applications, higher-end models like the PERC H740P or H840 are recommended. These models offer faster performance, larger cache sizes, and more advanced data protection features. However, for smaller businesses or less demanding workloads, models like the PERC H330 provide a more affordable yet effective solution.