1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 Kernel driver drivetemp 3 Kernel driver drivetemp
4 ======================= 4 =======================
5 5
6 6
7 References 7 References
8 ---------- 8 ----------
9 9
10 ANS T13/1699-D 10 ANS T13/1699-D
11 Information technology - AT Attachment 8 - ATA 11 Information technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)
12 12
13 ANS Project T10/BSR INCITS 513 13 ANS Project T10/BSR INCITS 513
14 Information technology - SCSI Primary Commands 14 Information technology - SCSI Primary Commands - 4 (SPC-4)
15 15
16 ANS Project INCITS 557 16 ANS Project INCITS 557
17 Information technology - SCSI / ATA Translatio 17 Information technology - SCSI / ATA Translation - 5 (SAT-5)
18 18
19 19
20 Description 20 Description
21 ----------- 21 -----------
22 22
23 This driver supports reporting the temperature 23 This driver supports reporting the temperature of disk and solid state
24 drives with temperature sensors. 24 drives with temperature sensors.
25 25
26 If supported, it uses the ATA SCT Command Tran 26 If supported, it uses the ATA SCT Command Transport feature to read
27 the current drive temperature and, if availabl 27 the current drive temperature and, if available, temperature limits
28 as well as historic minimum and maximum temper 28 as well as historic minimum and maximum temperatures. If SCT Command
29 Transport is not supported, the driver uses SM 29 Transport is not supported, the driver uses SMART attributes to read
30 the drive temperature. 30 the drive temperature.
31 31
32 32
33 Usage Note 33 Usage Note
34 ---------- 34 ----------
35 35
36 Reading the drive temperature may reset the sp 36 Reading the drive temperature may reset the spin down timer on some drives.
37 This has been observed with WD120EFAX drives, 37 This has been observed with WD120EFAX drives, but may be seen with other
38 drives as well. The same behavior is observed 38 drives as well. The same behavior is observed if the 'hdtemp' or 'smartd'
39 tools are used to access the drive. 39 tools are used to access the drive.
40 With the WD120EFAX drive, reading the drive te 40 With the WD120EFAX drive, reading the drive temperature using the drivetemp
41 driver is still possible _after_ it transition 41 driver is still possible _after_ it transitioned to standby mode, and
42 reading the drive temperature in this mode wil 42 reading the drive temperature in this mode will not cause the drive to
43 change its mode (meaning the drive will not sp 43 change its mode (meaning the drive will not spin up). It is unknown if other
44 drives experience similar behavior. 44 drives experience similar behavior.
45 45
46 A known workaround for WD120EFAX drives is to 46 A known workaround for WD120EFAX drives is to read the drive temperature at
47 intervals larger than twice the spin-down time 47 intervals larger than twice the spin-down time. Otherwise affected drives
48 will never spin down. 48 will never spin down.
49 49
50 50
51 Sysfs entries 51 Sysfs entries
52 ------------- 52 -------------
53 53
54 Only the temp1_input attribute is always avail 54 Only the temp1_input attribute is always available. Other attributes are
55 available only if reported by the drive. All t 55 available only if reported by the drive. All temperatures are reported in
56 milli-degrees Celsius. 56 milli-degrees Celsius.
57 57
58 ======================= ====================== 58 ======================= =====================================================
59 temp1_input Current drive temperat 59 temp1_input Current drive temperature
60 temp1_lcrit Minimum temperature li 60 temp1_lcrit Minimum temperature limit. Operating the device below
61 this temperature may c 61 this temperature may cause physical damage to the
62 device. 62 device.
63 temp1_min Minimum recommended co 63 temp1_min Minimum recommended continuous operating limit
64 temp1_max Maximum recommended co 64 temp1_max Maximum recommended continuous operating temperature
65 temp1_crit Maximum temperature li 65 temp1_crit Maximum temperature limit. Operating the device above
66 this temperature may c 66 this temperature may cause physical damage to the
67 device. 67 device.
68 temp1_lowest Minimum temperature se 68 temp1_lowest Minimum temperature seen this power cycle
69 temp1_highest Maximum temperature se 69 temp1_highest Maximum temperature seen this power cycle
70 ======================= ====================== 70 ======================= =====================================================
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.