HP Smart Array Controller technology, 4th edition

Introduction

In 1989, HP (then Compaq) was the first company to introduce RAID subsystems in the network server

marketplace. Today, RAID is an industry-standard technology used for most online network data storage.

Our Smart Array controllers support RAID levels 0, 1, 1+0, 5, 6, 50, and 60.

HP engineers continue to enhance Smart Array performance, expansion, migration, and data availability

capabilities. We provide administrators with tools for Smart Array configuration, storage management, and

diagnostics. These tools make it easy to use Smart Array products as well as making interfaces and feature

sets consistent between product generations. Consistent features sets ensure that you can move data

between servers and external storage enclosures, and between models of Smart Array controllers.

This paper discusses the Smart Array processor engine, RAID level selection, data availability, fault

tolerance, and recovery mechanisms. These capabilities allow Smart Array controllers to sustain high I/O

throughput in a reliable, predictable way.

References made in this technology brief to the “present generation” of Smart Array controllers refer to the

P410i, P410, P411, P212, P712, and P812. We began releasing these SAS-based, PCIe 2.0-compliant

Smart Array controllers in 2009.

Smart Array performance factors

HP Smart Array hardware performance depends on multiple, interdependent factors.

We’ve enhanced Smart Array hardware performance with:

 Multi-core multi-processing engine

 Hardware tuning that includes customized connection settings

 Advanced caching capabilities

Standard technologies that contribute to Smart Array performance include:

 PCIe bus

 Serial Attached SCSI (SAS) and its interoperability with Serial Advanced Technology Attachment (SATA)

devices

 SAS-2 enhancements to cabling and connectors

 SAS topologies and zoning

Smart Array processing engine

The Smart Array multi-core multi-processing engine manages the RAID system. It transforms high-level read

or write requests from an application into the individual instructions required for the RAID array. The current

generation Smart Array controllers use an embedded RAID-on-Chip (RoC) processor running at 600 MHz.

While it is not a direct measure of overall RAID performance, the new processor is capable of supporting

up to 60,000 4 KiB random IOPS compared to 35,000 for the previous generation engines.

NOTE:

KiB, MiB, and GiB are measurement units established by the International

Electrotechnical Commission (IEC) and accepted by all major standards

organizations. They replace the use of KB, MB, and GB. You may see both

acronym types, along with other acronym replacements, as we update our tools,

user interfaces, and documentation.