CHAPTER 7 ERROR ANALYSIS

7.1Error Analysis Information Collection

7.2Sense Data Analysis

This chapter explains in detail how sense data collected from a disk drive is used for troubleshooting. Sense data reflects an error in the disk drive, and helps with troubleshooting.

A sense key, additional sense code, and additional sense code qualifier, taken from various sense data are repeated. Also in this chapter, troubleshooting is performed using these three codes. Unless otherwise specified, "sense data" means the above three codes. When sense data is represented as (x-xx-xx), the leftmost x is a sense key, the middle xx is an additional sense code, and the rightmost x is an additional sense code qualifier.

7.1Error Analysis Information Collection

7.1.1Sense data

When the HDD posts a CHECK CONDITION status or detects a fatal error in the SCSI bus, the current command or queued command is cleared. In such a case, the HDD generates sense data about the command-issuing initiator. The initiator can read the sense data by issuing a REQUEST SENSE command.

Even if a transfer byte length that is shorter than the sense data length of the tested device is specified, the command terminates normally. In this case, however, the initiator receives part of the sense data, but the remaining part of the sense data is lost.

For details of the REQUEST SENSE command, refer to Subsection 3.1.15 “REQUEST SENSE(15)” of the SCSI Logical Interface Specifications.

7.1.2Sense key, additional sense code, and additional sense code qualifier

If an error is detected in a disk drive, the error status is indicated in the sense data collected from the disk drive. Figure 7.1 shows the positions of a sense key, additional sense code, and additional sense code qualifier.

C141-E226

7-1

Page 113
Image 113
Fujitsu MAW3147NC/NP, MAW3300NC/NP, MAW3073NC/NP manual Error Analysis Information Collection Sense Data Analysis

MAW3147NC/NP, MAW3073NC/NP, MAW3300NC/NP specifications

Fujitsu has established itself as a key player in the world of hard disk drives, and their MAW3073NC/NP, MAW3300NC/NP, and MAW3147NC/NP models showcase exemplary engineering and innovative technology. These drives are designed primarily for enterprise applications, providing robust performance, reliability, and data integrity in demanding environments.

One of the standout features of the Fujitsu MAW series is its high storage capacity. The MAW3073NC/NP model comes with a generous 73 GB capacity, while the MAW3300NC/NP boasts 300 GB, and the MAW3147NC/NP offers 147 GB of storage. This range makes them suitable for various applications, from databases to data-intensive software.

The drives utilize the latest Serial Attached SCSI (SAS) interface, which ensures high speed and efficiency in data transfer. SAS technology provides better bandwidth and performance compared to older parallel SCSI interfaces, enabling faster access to data and improved overall system responsiveness. With rotational speeds of 10,000 RPM, these drives further enhance performance, enabling faster read and write times, which is critical for enterprise applications that require quick data retrieval.

Another noteworthy characteristic of the Fujitsu MAW series is their advanced error recovery and data integrity features. The drives are equipped with sophisticated error correction mechanisms and management systems that help maintain data integrity, ensuring that the data remains intact even in the event of power loss or system failure. This reliability is paramount for enterprise environments where data loss can result in significant operational disruptions.

In terms of physical design, these drives are built to endure the rigors of high-demand environments. They feature a robust construction that allows for efficient heat dissipation, minimizing the risks associated with overheating. Additionally, their form factor is designed for easy integration into various server and storage systems, making them versatile solutions for IT infrastructure.

Fujitsu's commitment to sustainability is also evident in the MAW series with their energy-efficient operation and reduced power consumption, contributing to decreased overall operational costs. With a combination of high performance, reliability, and sustainability, the Fujitsu MAW3073NC/NP, MAW3300NC/NP, and MAW3147NC/NP hard drives stand out as formidable choices for organizations looking to optimize their data storage solutions. They embody the cutting-edge technology and quality that Fujitsu is known for in the enterprise storage market.