PowerEdge: High SMART Error Rates for Read and Verify ECC Errors on Certain Enterprise Hard Drives

Table of Contents

1. Introduction
2. Description
3. Solution
4. Further Information

 

Introduction

S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology; often written as SMART) is a health monitoring system for hard drives and solid state drives which has been internationally standardized.

SMART's primary function is to detect and report drive reliability indicators, anticipating failures to allow hardware replacement before failure and maintain data integrity.

Dell has collaborated with our hard drive vendors in the interpretation of these values.
 

Description

Reviewing the SMART status of some enterprise hard drives revealed high read and verifying ECC correction rates on certain models. Comparing these values with other hard drives may suggest that some models have a higher error rate than others, which may report zero ECC corrections.
Sometimes this error rate appears as hundreds of millions of ECC corrections and may increment rapidly as more I/O transactions occur.

An example of this situation is provided below. This example was gathered by running the command "smartctl -a /dev/sdX" under Linux OS.
 
Figure 1: Error Counter Log

Solution

The SMART specification allows vendors to provide these counters, such as the ones shown in the above example, for informational purposes. The counters are not necessarily a count of soft or hard faults within the ECC logic. This allows each drive vendor flexibility as to what is displayed in the available SMART fields. For some vendors, no error data is in the ECC read or verify categories. In the example above, the vendor has chosen to use the counters for monitoring the ECC functionality. The values which are presented do not represent an error-rate. Similarly, a higher rate of events on some disks in comparison to others does not indicate that a performance problem exists.
 

For specific queries about health counters on an Enterprise hard drive model, contact our support technicians to get answers from Dell Technologies' engineering teams.

.

Further Information

• For more information about the international standardization of SMART values and other SCSI Storage Interfaces see the home page of the T10 technical committee located here.
• Smartmontools is a utility to control and monitor computer storage systems using the Self-Monitoring, Analysis, and Reporting Technology system built into most modern ATA, Serial ATA, SCSI/SAS and NVMe hard drives. It is not a Dell tool. More information about Smartmontools can be found here.