sysfs-block-device 2.1 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960
  1. What: /sys/block/*/device/sw_activity
  2. Date: Jun, 2008
  3. KernelVersion: v2.6.27
  4. Contact: linux-ide@vger.kernel.org
  5. Description:
  6. (RW) Used by drivers which support software controlled activity
  7. LEDs.
  8. It has the following valid values:
  9. == ========================================================
  10. 0 OFF - the LED is not activated on activity
  11. 1 BLINK_ON - the LED blinks on every 10ms when activity is
  12. detected.
  13. 2 BLINK_OFF - the LED is on when idle, and blinks off
  14. every 10ms when activity is detected.
  15. == ========================================================
  16. Note that the user must turn sw_activity OFF it they wish to
  17. control the activity LED via the em_message file.
  18. What: /sys/block/*/device/unload_heads
  19. Date: Sep, 2008
  20. KernelVersion: v2.6.28
  21. Contact: linux-ide@vger.kernel.org
  22. Description:
  23. (RW) Hard disk shock protection
  24. Writing an integer value to this file will take the heads of the
  25. respective drive off the platter and block all I/O operations
  26. for the specified number of milliseconds.
  27. - If the device does not support the unload heads feature,
  28. access is denied with -EOPNOTSUPP.
  29. - The maximal value accepted for a timeout is 30000
  30. milliseconds.
  31. - A previously set timeout can be cancelled and disk can resume
  32. normal operation immediately by specifying a timeout of 0.
  33. - Some hard drives only comply with an earlier version of the
  34. ATA standard, but support the unload feature nonetheless.
  35. There is no safe way Linux can detect these devices, so this
  36. is not enabled by default. If it is known that your device
  37. does support the unload feature, then you can tell the kernel
  38. to enable it by writing -1. It can be disabled again by
  39. writing -2.
  40. - Values below -2 are rejected with -EINVAL
  41. For more information, see
  42. Documentation/admin-guide/laptops/disk-shock-protection.rst
  43. What: /sys/block/*/device/ncq_prio_enable
  44. Date: Oct, 2016
  45. KernelVersion: v4.10
  46. Contact: linux-ide@vger.kernel.org
  47. Description:
  48. (RW) Write to the file to turn on or off the SATA ncq (native
  49. command queueing) support. By default this feature is turned
  50. off.