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sysfs-block-device

sysfs-block-device 2.0 KB
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  1. What:		/sys/block/*/device/sw_activity
    2. 

  2. Date:		Jun, 2008
    3. 

  3. KernelVersion:	v2.6.27
    4. 

  4. Contact:	linux-ide@vger.kernel.org
    5. 

  5. Description:
    6. 

  6. 		(RW) Used by drivers which support software controlled activity
    7. 

  7. 		LEDs.
    8. 

  8. 

  9. 		It has the following valid values:
    10. 

  10. 

  11. 		0	OFF - the LED is not activated on activity
    12. 

  12. 		1	BLINK_ON - the LED blinks on every 10ms when activity is
    13. 

  13. 			detected.
    14. 

  14. 		2	BLINK_OFF - the LED is on when idle, and blinks off
    15. 

  15. 			every 10ms when activity is detected.
    16. 

  16. 

  17. 		Note that the user must turn sw_activity OFF it they wish to
    18. 

  18. 		control the activity LED via the em_message file.
    19. 

  19. 

  20. 

  21. What:		/sys/block/*/device/unload_heads
    22. 

  22. Date:		Sep, 2008
    23. 

  23. KernelVersion:	v2.6.28
    24. 

  24. Contact:	linux-ide@vger.kernel.org
    25. 

  25. Description:
    26. 

  26. 		(RW) Hard disk shock protection
    27. 

  27. 

  28. 		Writing an integer value to this file will take the heads of the
    29. 

  29. 		respective drive off the platter and block all I/O operations
    30. 

  30. 		for the specified number of milliseconds.
    31. 

  31. 

  32. 		- If the device does not support the unload heads feature,
    33. 

  33. 		  access is denied with -EOPNOTSUPP.
    34. 

  34. 		- The maximal value accepted for a timeout is 30000
    35. 

  35. 		  milliseconds.
    36. 

  36. 		- A previously set timeout can be cancelled and disk can resume
    37. 

  37. 		  normal operation immediately by specifying a timeout of 0.
    38. 

  38. 		- Some hard drives only comply with an earlier version of the
    39. 

  39. 		  ATA standard, but support the unload feature nonetheless.
    40. 

  40. 		  There is no safe way Linux can detect these devices, so this
    41. 

  41. 		  is not enabled by default. If it is known that your device
    42. 

  42. 		  does support the unload feature, then you can tell the kernel
    43. 

  43. 		  to enable it by writing -1. It can be disabled again by
    44. 

  44. 		  writing -2.
    45. 

  45. 		- Values below -2 are rejected with -EINVAL
    46. 

  46. 

  47. 		For more information, see
    48. 

  48. 		Documentation/laptops/disk-shock-protection.txt
    49. 

  49. 

  50. 

  51. What:		/sys/block/*/device/ncq_prio_enable
    52. 

  52. Date:		Oct, 2016
    53. 

  53. KernelVersion:	v4.10
    54. 

  54. Contact:	linux-ide@vger.kernel.org
    55. 

  55. Description:
    56. 

  56. 		(RW) Write to the file to turn on or off the SATA ncq (native
    57. 

  57. 		command queueing) support. By default this feature is turned
    58. 

  58. 		off.
    59.