Smart hard disk status detection

Smart Introduction

S. M. A. R. T. is called self-monitoring analysis and reporting technology ". It is an automatic hardware status detection and warning system and specification. Monitor and record the running status of hardware, such as head, disk, motor, and circuit, and compare it with the preset security value set by the manufacturer, if the monitoring condition is beyond the security range of the preset security value, you can automatically warn the user through the host monitoring hardware or software and perform minor Automatic repair, to guarantee the security of hard disk data in advance. In addition to some hard disks that have been released very early, most hard disks are now equipped with this technology.

Smartmontools

• Project home: http://www.smartmontools.org/
• Function Description: smartmontools is an open-source Disk control and monitoring tool that runs on Linux, UNIX, BSD, Solaris, Mac OS, OS/2, cygwin, and windows, it can also run from the boot disc or boot floppy disk, supporting ATA/atapi/SATA-3 (to-8) bit hard disk and SCSI hard disk, as well as tape equipment, it mainly includes two utilities: smartctl and smatd.

The hard disk it monitors must have S. m.a. r. t feature. Currently, all hard disks have this feature, but this feature is not enabled by default. There are two ways to enable this feature:

• Set options through BIOS
• Use the smartctl command. It can be used to test the health status of the hard disk and provide early warnings before a fault occurs.

Basic use of smartctl

• Smartctl-Scan
• Smartctl-I/dev/SDA
• Smartctl-H/dev/SDA
• Smartctl-A/dev/SDA
• Smartctl-A/dev/SDA

Smart attributes

Smart attributes include critical attributes and informative attributes, key attributes and information attributes.
The key attributes include the most important data about hard disk health, while the data provided by the information attributes is generally auxiliary. To distinguish them, you can view threshold (threshold/limit value). A non-zero value indicates a key attribute, and a zero value indicates an information attribute.

Description of smart values

* The current value of value * the worst value of worst, which can be understood as the peak value of a certain item * raw values/data and the total value of data associated with an attribute * threshold/limit value: if a property exceeds the limit value specified by threshold, it indicates that your hard disk is faulty. * Status: OK: value is normal/OK: Always passing indicates normal; warning and pre-failure indicate that a fault may occur. Bad or failed indicates that a fault has occurred.

Each drive manufacturer defines a set of properties and sets a threshold value. exceeding this property should not pass through normal operations. Each attribute has an original value, which means that the value is completely normalized by the drive manufacturer (but usually corresponds to the count or physical unit, such as degrees Celsius or seconds). The value range is 1 ~ 253 (in general, 1 represents the worst case and 253 represents the best) and the most difference, it represents the lowest record, normalization value. According to different manufacturers, the values of 100 or 200 are often selected as the initial standard value. Manufacturers that have implemented at least one smart attribute in a variety of products include Samsung, Seagate, IBM (HITACHI), Fujitsu, Mattel, Toshiba, Intel, Stec, and Western data and yituo technology.

Important key attributes

In general, if the following 10 indicators start to change significantly, it indicates that the hard disk is starting to enter an unstable state and may even stop working at any time.

No.	Hexadecimal value	Name	Optimal status	Chinese name
01	0x01	Read Error Rate	Lower, better	Underlying data read error rate
05	0x05	Reallocated sectors count	Lower, better	Sector statistical value for reallocation
10	0x0a	Spin retry count	Lower, better	Number of start-to-start retry attempts
184	0xb8	End-to-End error/ioedc	Lower, better	End-to-End Error
188	0xbc	Command timeout	Lower, better	Command timeout
196	0xc4	Reallocation event count	Lower, better	Remap operation count
197	0xc5	Current pending sector count	Lower, better	Currently waiting sector count
198	0xc6	Offline uncorrectable	Lower, better	Total number of unrecoverable sectors
201	0xc9	Soft read error rate	Lower, better	Soft read/write error rate
230	0xe6	Drive Life Protection Status	Higher and better	Drive Life Protection Status

References

• Http://zh.wikipedia.org/wiki/S.M.A.R.T.
• Http://en.wikipedia.org/wiki/Comparison_of_S.M.A.R.T._tools
• Http://en.wikipedia.org/wiki/Self-Monitoring%2C_Analysis%2C_and_Reporting_Technology
• Http://www.hdsentinel.com/smart/

Smart hard disk status detection