![读取SMART数据-这是什么意思?](https://linux22.com/image/1570325/%E8%AF%BB%E5%8F%96SMART%E6%95%B0%E6%8D%AE-%E8%BF%99%E6%98%AF%E4%BB%80%E4%B9%88%E6%84%8F%E6%80%9D%EF%BC%9F.png)
我把这个驱动器连接到 raspi 上,突然变得非常慢。在另一个网站上,有人建议运行,smartctl -a /dev/sdc
但我不知道我在看什么以及如何修复它(如果可能的话)
$ sudo smartctl -a /dev/sdc
smartctl 6.6 2016-05-31 r4324 [armv7l-linux-4.14.62-v7+] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Seagate Barracuda 7200.14 (AF)
Device Model: ST2000DM001-1E6164
Serial Number: W1E66VJ8
LU WWN Device Id: 5 000c50 03d263f01
Firmware Version: SC48
User Capacity: 2,000,398,934,016 bytes [2.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 7200 rpm
Form Factor: 3.5 inches
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Wed Sep 12 23:34:28 2018 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
Read SMART Data failed: Connection timed out
=== START OF READ SMART DATA SECTION ===
SMART Status command failed: Connection timed out
SMART overall-health self-assessment test result: UNKNOWN!
SMART Status, Attributes and Thresholds cannot be read.
SMART Error Log Version: 1
ATA Error Count: 620 (device log contains only the most recent five errors)
CR = Command Register [HEX]
FR = Features Register [HEX]
SC = Sector Count Register [HEX]
SN = Sector Number Register [HEX]
CL = Cylinder Low Register [HEX]
CH = Cylinder High Register [HEX]
DH = Device/Head Register [HEX]
DC = Device Command Register [HEX]
ER = Error register [HEX]
ST = Status register [HEX]
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.
Error 620 occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 ff ff ff 0f Error: UNC at LBA = 0x0fffffff = 268435455
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
25 00 08 ff ff ff 4f 00 00:28:57.935 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:49.641 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:49.021 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.238 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.084 READ DMA EXT
Error 619 occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 ff ff ff 0f Error: UNC at LBA = 0x0fffffff = 268435455
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
25 00 08 ff ff ff 4f 00 00:28:57.935 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:49.641 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:49.021 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.238 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.084 READ DMA EXT
Error 618 occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 ff ff ff 0f Error: UNC at LBA = 0x0fffffff = 268435455
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
25 00 08 ff ff ff 4f 00 00:28:49.641 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:49.021 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.238 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.084 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.083 READ DMA EXT
Error 617 occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 ff ff ff 0f Error: UNC at LBA = 0x0fffffff = 268435455
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
25 00 08 ff ff ff 4f 00 00:28:49.641 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:49.021 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.238 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.084 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:28:48.083 READ DMA EXT
Error 616 occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 ff ff ff 0f Error: UNC at LBA = 0x0fffffff = 268435455
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
25 00 08 ff ff ff 4f 00 00:27:28.523 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:27:25.103 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:27:25.102 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:27:25.102 READ DMA EXT
25 00 08 ff ff ff 4f 00 00:27:25.101 READ DMA EXT
SMART Self-test log structure revision number 1
No self-tests have been logged. [To run self-tests, use: smartctl -t]
Selective Self-tests/Logging not supported
pi@soul:/media/d $ sudo smartctl -t /dev/sdc
smartctl 6.6 2016-05-31 r4324 [armv7l-linux-4.14.62-v7+] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org
=======> INVALID ARGUMENT TO -t: /dev/sdc
=======> VALID ARGUMENTS ARE: offline, short, long, conveyance, force, vendor,N, select,M-N, pending,N, afterselect,[on|off] <=======
Use smartctl -h to get a usage summary
sudo smartctl -x /dev/sdc
smartctl 6.6 2016-05-31 r4324 [armv7l-linux-4.14.62-v7+] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Seagate Barracuda 7200.14 (AF)
Device Model: ST2000DM001-1E6164
Serial Number: W1E66VJ8
LU WWN Device Id: 5 000c50 03d263f01
Firmware Version: SC48
User Capacity: 2,000,398,934,016 bytes [2.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 7200 rpm
Form Factor: 3.5 inches
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Wed Sep 12 23:39:37 2018 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
AAM feature is: Unavailable
APM level is: 128 (minimum power consumption without standby)
Rd look-ahead is: Enabled
Write cache is: Enabled
ATA Security is: Disabled, NOT FROZEN [SEC1]
Wt Cache Reorder: Unavailable
Read SMART Data failed: Connection timed out
=== START OF READ SMART DATA SECTION ===
SMART Status command failed: Connection timed out
SMART overall-health self-assessment test result: UNKNOWN!
SMART Status, Attributes and Thresholds cannot be read.
General Purpose Log Directory Version 1
SMART Log Directory Version 1 [multi-sector log support]
Address Access R/W Size Description
0x00 GPL,SL R/O 1 Log Directory
0x01 SL R/O 1 Summary SMART error log
0x02 SL R/O 5 Comprehensive SMART error log
0x03 GPL R/O 5 Ext. Comprehensive SMART error log
0x06 SL R/O 1 SMART self-test log
0x07 GPL R/O 1 Extended self-test log
0x09 SL R/W 1 Selective self-test log
0x11 GPL R/O 1 SATA Phy Event Counters log
0x21 GPL R/O 1 Write stream error log
0x22 GPL R/O 1 Read stream error log
0x80-0x9f GPL,SL R/W 16 Host vendor specific log
0xa1 GPL,SL VS 20 Device vendor specific log
0xa2 GPL VS 4496 Device vendor specific log
0xa8 GPL,SL VS 129 Device vendor specific log
0xa9 GPL,SL VS 1 Device vendor specific log
0xab GPL VS 1 Device vendor specific log
0xb0 GPL VS 5176 Device vendor specific log
0xbd GPL VS 512 Device vendor specific log
0xbe-0xbf GPL VS 65535 Device vendor specific log
0xc0 GPL,SL VS 1 Device vendor specific log
0xc1 GPL,SL VS 10 Device vendor specific log
0xe0 GPL,SL R/W 1 SCT Command/Status
0xe1 GPL,SL R/W 1 SCT Data Transfer
SMART Extended Comprehensive Error Log Version: 1 (5 sectors)
Device Error Count: 620 (device log contains only the most recent 20 errors)
CR = Command Register
FEATR = Features Register
COUNT = Count (was: Sector Count) Register
LBA_48 = Upper bytes of LBA High/Mid/Low Registers ] ATA-8
LH = LBA High (was: Cylinder High) Register ] LBA
LM = LBA Mid (was: Cylinder Low) Register ] Register
LL = LBA Low (was: Sector Number) Register ]
DV = Device (was: Device/Head) Register
DC = Device Control Register
ER = Error register
ST = Status register
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.
Error 620 [19] occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 00 3c 6c 41 40 00 00 Error: UNC at LBA = 0x3c6c4140 = 1013727552
Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
25 00 00 00 08 00 00 3c 6c 41 40 40 00 00:28:57.935 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 41 40 40 00 00:28:49.641 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 41 38 40 00 00:28:49.021 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 68 40 00 00:28:48.238 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 60 40 00 00:28:48.084 READ DMA EXT
Error 619 [18] occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 00 3c 6c 41 40 00 00 Error: UNC at LBA = 0x3c6c4140 = 1013727552
Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
25 00 00 00 08 00 00 3c 6c 41 40 40 00 00:28:57.935 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 41 40 40 00 00:28:49.641 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 41 38 40 00 00:28:49.021 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 68 40 00 00:28:48.238 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 60 40 00 00:28:48.084 READ DMA EXT
Error 618 [17] occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 00 3c 6c 41 40 00 00 Error: UNC at LBA = 0x3c6c4140 = 1013727552
Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
25 00 00 00 08 00 00 3c 6c 41 40 40 00 00:28:49.641 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 41 38 40 00 00:28:49.021 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 68 40 00 00:28:48.238 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 60 40 00 00:28:48.084 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 58 40 00 00:28:48.083 READ DMA EXT
Error 617 [16] occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 00 3c 6c 41 40 00 00 Error: UNC at LBA = 0x3c6c4140 = 1013727552
Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
25 00 00 00 08 00 00 3c 6c 41 40 40 00 00:28:49.641 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 41 38 40 00 00:28:49.021 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 68 40 00 00:28:48.238 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 60 40 00 00:28:48.084 READ DMA EXT
25 00 00 00 08 00 00 3c 6c 40 58 40 00 00:28:48.083 READ DMA EXT
Error 616 [15] occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 00 3c 69 fa 70 00 00 Error: UNC at LBA = 0x3c69fa70 = 1013578352
Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
25 00 00 00 08 00 00 3c 69 fa 70 40 00 00:27:28.523 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 70 40 00 00:27:25.103 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 68 40 00 00:27:25.102 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 60 40 00 00:27:25.102 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 58 40 00 00:27:25.101 READ DMA EXT
Error 615 [14] occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 00 3c 69 fa 70 00 00 Error: UNC at LBA = 0x3c69fa70 = 1013578352
Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
25 00 00 00 08 00 00 3c 69 fa 70 40 00 00:27:28.523 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 70 40 00 00:27:25.103 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 68 40 00 00:27:25.102 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 60 40 00 00:27:25.102 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 58 40 00 00:27:25.101 READ DMA EXT
Error 614 [13] occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 00 3c 69 fa 70 00 00 Error: UNC at LBA = 0x3c69fa70 = 1013578352
Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
25 00 00 00 08 00 00 3c 69 fa 70 40 00 00:27:25.103 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 68 40 00 00:27:25.102 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 60 40 00 00:27:25.102 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 58 40 00 00:27:25.101 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 50 40 00 00:27:25.100 READ DMA EXT
Error 613 [12] occurred at disk power-on lifetime: 37859 hours (1577 days + 11 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 00 3c 69 fa 70 00 00 Error: UNC at LBA = 0x3c69fa70 = 1013578352
Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
25 00 00 00 08 00 00 3c 69 fa 70 40 00 00:27:25.103 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 68 40 00 00:27:25.102 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 60 40 00 00:27:25.102 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 58 40 00 00:27:25.101 READ DMA EXT
25 00 00 00 08 00 00 3c 69 fa 50 40 00 00:27:25.100 READ DMA EXT
SMART Extended Self-test Log Version: 1 (1 sectors)
No self-tests have been logged. [To run self-tests, use: smartctl -t]
Selective Self-tests/Logging not supported
SCT Status Version: 3
SCT Version (vendor specific): 522 (0x020a)
SCT Support Level: 1
Device State: Active (0)
Current Temperature: 45 Celsius
Power Cycle Min/Max Temperature: 40/47 Celsius
Lifetime Min/Max Temperature: 18/58 Celsius
Under/Over Temperature Limit Count: 0/0
SCT Data Table command not supported
SCT Error Recovery Control command not supported
Device Statistics (GP/SMART Log 0x04) not supported
SATA Phy Event Counters (GP Log 0x11)
ID Size Value Description
0x000a 2 911 Device-to-host register FISes sent due to a COMRESET
0x0001 2 0 Command failed due to ICRC error
0x0003 2 0 R_ERR response for device-to-host data FIS
0x0004 2 0 R_ERR response for host-to-device data FIS
0x0006 2 0 R_ERR response for device-to-host non-data FIS
0x0007 2 0 R_ERR response for host-to-device non-data FIS
答案1
看到很多“读取 SMART 数据失败:连接超时-A, --attributes
“消息,这可能不寻常。由于某种原因,看起来它们没有被阅读。
无论如何,你不必亲自研究所有数字,你可以尝试使用类似gsmartctrl
“smartctl 的图形用户界面”。它有一些特征喜欢:
- 自动报告并突出显示任何异常;
- 执行 SMART 自我测试;
- 显示驱动器身份信息、功能、属性、设备统计信息等...;
- 可以从保存的文件中读取 smartctl 输出,将其解释为只读虚拟设备;
- 有详细的帮助信息。
smartctl 的手册页有一些关于 SMART 属性的信息,看起来原始值可能并不总是以明显的方式直接对应于属性,下面是摘录:
Each Attribute has a "Raw" value, printed under the heading
"RAW_VALUE", and a "Normalized" value printed under the heading
"VALUE". [Note: smartctl prints these values in base-10.] In the
example just given, the "Raw Value" for Attribute 12 would be the
actual number of times that the disk has been power-cycled, for
example 365 if the disk has been turned on once per day for exactly
one year. Each vendor uses their own algorithm to convert this
"Raw" value to a "Normalized" value in the range from 1 to 254.
Please keep in mind that smartctl only reports the different
Attribute types, values, and thresholds as read from the device. It
does not carry out the conversion between "Raw" and "Normalized"
values: this is done by the disk´s firmware.
The conversion from Raw value to a quantity with physical units is
not specified by the SMART standard. In most cases, the values
printed by smartctl are sensible. For example the temperature
Attribute generally has its raw value equal to the temperature in
Celsius. However in some cases vendors use unusual conventions.
For example the Hitachi disk on my laptop reports its power-on hours
in minutes, not hours. Some IBM disks track three temperatures
rather than one, in their raw values. And so on.
...
Please note: the fact
that an Attribute is of type 'Pre-fail' does not mean that your disk
is about to fail! It only has this meaning if the Attribute´s cur‐
rent Normalized value is less than or equal to the threshold value.
...
If the Attribute´s current Normalized value is less than or equal to
the threshold value, then the "WHEN_FAILED" column will display
"FAILING_NOW". If not, but the worst recorded value is less than or
equal to the threshold value, then this column will display
"In_the_past". If the "WHEN_FAILED" column has no entry (indicated
by a dash: ´-´) then this Attribute is OK now (not failing) and has
also never failed in the past.
...
So to summarize: the Raw Attribute values are the ones that might
have a real physical interpretation, such as "Temperature Celsius",
"Hours", or "Start-Stop Cycles". Each manufacturer converts these,
using their detailed knowledge of the disk´s operations and failure
modes, to Normalized Attribute values in the range 1-254. The cur‐
rent and worst (lowest measured) of these Normalized Attribute val‐
ues are stored on the disk, along with a Threshold value that the
manufacturer has determined will indicate that the disk is going to
fail, or that it has exceeded its design age or aging limit.
smartctl does not calculate any of the Attribute values, thresholds,
or types, it merely reports them from the SMART data on the device.