What: /sys/block/*/device/sw_activity
Date: Jun, 2008
KernelVersion: v2.6.27
Contact: [email protected]
Description:
(RW) Used by drivers which support software controlled activity
LEDs.
It has the following valid values:
== ========================================================
0 OFF - the LED is not activated on activity
1 BLINK_ON - the LED blinks on every 10ms when activity is
detected.
2 BLINK_OFF - the LED is on when idle, and blinks off
every 10ms when activity is detected.
== ========================================================
Note that the user must turn sw_activity OFF it they wish to
control the activity LED via the em_message file.
What: /sys/block/*/device/unload_heads
Date: Sep, 2008
KernelVersion: v2.6.28
Contact: [email protected]
Description:
(RW) Hard disk shock protection
Writing an integer value to this file will take the heads of the
respective drive off the platter and block all I/O operations
for the specified number of milliseconds.
- If the device does not support the unload heads feature,
access is denied with -EOPNOTSUPP.
- The maximal value accepted for a timeout is 30000
milliseconds.
- A previously set timeout can be cancelled and disk can resume
normal operation immediately by specifying a timeout of 0.
- Some hard drives only comply with an earlier version of the
ATA standard, but support the unload feature nonetheless.
There is no safe way Linux can detect these devices, so this
is not enabled by default. If it is known that your device
does support the unload feature, then you can tell the kernel
to enable it by writing -1. It can be disabled again by
writing -2.
- Values below -2 are rejected with -EINVAL
For more information, see
Documentation/admin-guide/laptops/disk-shock-protection.rst
What: /sys/block/*/device/ncq_prio_enable
Date: Oct, 2016
KernelVersion: v4.10
Contact: [email protected]
Description:
(RW) Write to the file to turn on or off the SATA NCQ (native
command queueing) priority support. By default this feature is
turned off. If the device does not support the SATA NCQ
priority feature, writing "1" to this file results in an error
(see ncq_prio_supported).
What: /sys/block/*/device/sas_ncq_prio_enable
Date: Oct, 2016
KernelVersion: v4.10
Contact: [email protected]
Description:
(RW) This is the equivalent of the ncq_prio_enable attribute
file for SATA devices connected to a SAS host-bus-adapter
(HBA) implementing support for the SATA NCQ priority feature.
This file does not exist if the HBA driver does not implement
support for the SATA NCQ priority feature, regardless of the
device support for this feature (see sas_ncq_prio_supported).
What: /sys/block/*/device/ncq_prio_supported
Date: Aug, 2021
KernelVersion: v5.15
Contact: [email protected]
Description:
(RO) Indicates if the device supports the SATA NCQ (native
command queueing) priority feature.
What: /sys/block/*/device/sas_ncq_prio_supported
Date: Aug, 2021
KernelVersion: v5.15
Contact: [email protected]
Description:
(RO) This is the equivalent of the ncq_prio_supported attribute
file for SATA devices connected to a SAS host-bus-adapter
(HBA) implementing support for the SATA NCQ priority feature.
This file does not exist if the HBA driver does not implement
support for the SATA NCQ priority feature, regardless of the
device support for this feature.
What: /sys/block/*/device/cdl_supported
Date: May, 2023
KernelVersion: v6.5
Contact: [email protected]
Description:
(RO) Indicates if the device supports the command duration
limits feature found in some ATA and SCSI devices.
What: /sys/block/*/device/cdl_enable
Date: May, 2023
KernelVersion: v6.5
Contact: [email protected]
Description:
(RW) For a device supporting the command duration limits
feature, write to the file to turn on or off the feature.
By default this feature is turned off.
Writing "1" to this file enables the use of command duration
limits for read and write commands in the kernel and turns on
the feature on the device. Writing "0" disables the feature.
Codebase Browser
linux