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 9 It has the following valid values: 10 11 == ======================================================== 12 0 OFF - the LED is not activated on activity 13 1 BLINK_ON - the LED blinks on every 10ms when activity is 14 detected. 15 2 BLINK_OFF - the LED is on when idle, and blinks off 16 every 10ms when activity is detected. 17 == ======================================================== 18 19 Note that the user must turn sw_activity OFF it they wish to 20 control the activity LED via the em_message file. 21 22 23 What: /sys/block/*/device/unload_heads 24 Date: Sep, 2008 25 KernelVersion: v2.6.28 26 Contact: linux-ide@vger.kernel.org 27 Description: 28 (RW) Hard disk shock protection 29 30 Writing an integer value to this file will take the heads of the 31 respective drive off the platter and block all I/O operations 32 for the specified number of milliseconds. 33 34 - If the device does not support the unload heads feature, 35 access is denied with -EOPNOTSUPP. 36 - The maximal value accepted for a timeout is 30000 37 milliseconds. 38 - A previously set timeout can be cancelled and disk can resume 39 normal operation immediately by specifying a timeout of 0. 40 - Some hard drives only comply with an earlier version of the 41 ATA standard, but support the unload feature nonetheless. 42 There is no safe way Linux can detect these devices, so this 43 is not enabled by default. If it is known that your device 44 does support the unload feature, then you can tell the kernel 45 to enable it by writing -1. It can be disabled again by 46 writing -2. 47 - Values below -2 are rejected with -EINVAL 48 49 For more information, see 50 Documentation/admin-guide/laptops/disk-shock-protection.rst 51 52 53 What: /sys/block/*/device/ncq_prio_enable 54 Date: Oct, 2016 55 KernelVersion: v4.10 56 Contact: linux-ide@vger.kernel.org 57 Description: 58 (RW) Write to the file to turn on or off the SATA ncq (native 59 command queueing) support. By default this feature is turned 60 off. 61