SMART Technologies: General Principles of Self-Diagnosis of Hard Drives

As you know, a hard disk on a computer plays one of the key roles, since it is he who is responsible for storing information, whether it's the operating system or user programs and files. And this particular component of the computer is subject to the greatest wear, since it is used almost every second. That's why most manufacturers of hard drives began to use the built-in SMART-diagnostics technologies, which would allow to check the disks regardless of the installed system. Let's try to figure out what it is.

What is SMART technology ?

Before we consider the technologies and functions associated with them, we turn to the deciphering of the abbreviation. SMART (for convenience we will use the SMART reduction) stands for Self-Monitoring, Analysis and Reporting Technology, that is, roughly speaking, it is a system of self-diagnostics, analysis and reporting.

Basic principles of diagnosis

If you approach the understanding of such technology in a broader sense, every user should know that it has nothing to do with the installed operating system. As a matter of fact, SMART technologies consist in application of a certain microprogram, which is built in HDD-controller at the stage of factory assembly. The program itself always works as long as the hard disk is functioning.

In this case, the evaluation of the hard disk includes tracking the main parameters of the state of the hard drive, the number of which can vary in different limits, but usually no more than thirty. The main monitored indicators include the speed of reading or writing data, the physical condition of the surface of the disk, some parameters related to the work of the mechanics of the hard drive, and so on.

But here's what's interesting: since in this case, to access the firmware to the disk, no cable connection or connection using loops is used, the internal check performed does not affect the CPU in any way. It is produced in the background, the indicator icon of access to the hard drive does not blink (or does not light constantly), but the noise produced by the hard disk is still sometimes heard. This is what surprises many users. Remember, there is nothing to worry about.

However, SMART technologies in the form of firmware, as a rule, in most cases use a quick check. At this stage, only the physical positioning of the hard drive and its electronic components are checked. It takes the whole process less than a minute. If, for any reason, failures occur, a full scan can be run, including both surface tests, and checking for bad clusters, and much more. Such processes take more time and can last about one hour.

At the same time, standard ATAPI / ATA commands are used to start any type of checks, and if a fault or fault is detected, a warning is issued, indicating some error (maybe even unrecoverable) with a suggestion to make a backup copy of the data. In most cases this just shows that the hard drive, to put it mildly, it's time to rest.

Setting SMART goals

As for setting tasks for the audits, here are a few basic parameters that will be tested in the course of autonomous diagnostics:

• Averaged value of the linear read and write speed;
• The average value of the time of transition to a certain track (positioning the head);
• Averaged reading of the random sector;
• The maximum time to perform a search in conditions of moving from the zero track to the last one;
• Read speed from the cache.

As for the cache, it should be said separately. In fact, it's a kind of own memory or a kind of clipboard. The data read from the hard drive is first written into the cache memory, and only then to the system memory via the corresponding controller on the "motherboard".

But all this concerned only the basic parameters. If to speak about the expanded check, here it is necessary to include the indicators, the fall of values of which can indicate wear of the disk:

• Number of sector reassignments;
• Total number of reassignment operations;
• The current number of unstable sectors;
• Frequency of errors during reading;
• The number of times the spindle is restarted;
• The number of non-correctable errors;
• Number of read / write errors;
• Number of spindle restart cycles;
• Working time in the switched-on state (in the worked hours since the start of operation);
• Number of complete start and stop cycles;
• Number of power-ups / downs.

Advantages and disadvantages

Actually, the technology itself, in which a microprogram is used to diagnose a hard disk, is welcomed by all. Its use allows you to perform a full hard drive test on time and prevent data loss.

But along with this there is one main disadvantage - the program itself does not eliminate the malfunction or errors that arise, but simply informs the owner that his disc is "dead". So about self-diagnosis, you should not flatter yourself. The result will be displayed only if the hard drive fails. In most cases, to deal with this is unrealistic, although there are some loopholes.

The most famous tools for diagnosing and recovering hard drives

Not paying attention to self-diagnostics, periodically it is necessary to use utilities for the control of a condition of the hard drive - though own means of operating systems, though third-party utilities. Built-in tools often cause a lot of criticism.

But here the program for diagnosing the hard disk of Victoria of any version today in computer technologies of this direction looks like an absolute leader.

A rather big resonance in its time caused the appearance of the most interesting utility HDD Regenerator, which, according to the developers, can bring to life any "dead" hard disk due to the magnetization reversal of the surface. It's hard to say how at the program level you can physically impact the surface, however the fact remains.

Conclusion

Finally it remains to add that only the main points concerning SMART technologies for autonomous diagnostics of hard drives are considered here. Specifically, no digression was made in the principles of performing such complex tests, since an untrained user in them, as they say, will break his head. However, he does not need it. It is enough to understand the basics that are embedded in the production, and self-monitoring of hard drives at the present stage of the development of computer technology.