drivetemp.rst 2.4 KB

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