| .. SPDX-License-Identifier: GPL-2.0 | |
| Kernel driver drivetemp | |
| ======================= | |
| References | |
| ---------- | |
| ANS T13/1699-D | |
| Information technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS) | |
| ANS Project T10/BSR INCITS 513 | |
| Information technology - SCSI Primary Commands - 4 (SPC-4) | |
| ANS Project INCITS 557 | |
| Information technology - SCSI / ATA Translation - 5 (SAT-5) | |
| Description | |
| ----------- | |
| This driver supports reporting the temperature of disk and solid state | |
| drives with temperature sensors. | |
| If supported, it uses the ATA SCT Command Transport feature to read | |
| the current drive temperature and, if available, temperature limits | |
| as well as historic minimum and maximum temperatures. If SCT Command | |
| Transport is not supported, the driver uses SMART attributes to read | |
| the drive temperature. | |
| Usage Note | |
| ---------- | |
| Reading the drive temperature may reset the spin down timer on some drives. | |
| This has been observed with WD120EFAX drives, but may be seen with other | |
| drives as well. The same behavior is observed if the 'hdtemp' or 'smartd' | |
| tools are used to access the drive. | |
| With the WD120EFAX drive, reading the drive temperature using the drivetemp | |
| driver is still possible _after_ it transitioned to standby mode, and | |
| reading the drive temperature in this mode will not cause the drive to | |
| change its mode (meaning the drive will not spin up). It is unknown if other | |
| drives experience similar behavior. | |
| A known workaround for WD120EFAX drives is to read the drive temperature at | |
| intervals larger than twice the spin-down time. Otherwise affected drives | |
| will never spin down. | |
| Sysfs entries | |
| ------------- | |
| Only the temp1_input attribute is always available. Other attributes are | |
| available only if reported by the drive. All temperatures are reported in | |
| milli-degrees Celsius. | |
| ======================= ===================================================== | |
| temp1_input Current drive temperature | |
| temp1_lcrit Minimum temperature limit. Operating the device below | |
| this temperature may cause physical damage to the | |
| device. | |
| temp1_min Minimum recommended continuous operating limit | |
| temp1_max Maximum recommended continuous operating temperature | |
| temp1_crit Maximum temperature limit. Operating the device above | |
| this temperature may cause physical damage to the | |
| device. | |
| temp1_lowest Minimum temperature seen this power cycle | |
| temp1_highest Maximum temperature seen this power cycle | |
| ======================= ===================================================== |