hdparm
Related articles
hdparm is a command line utility to set and view hardware parameters of hard disk drives. It can also be used as a simple benchmarking tool.
Contents
Installation
Install the hdparm package. For use with SCSI devices, install the sdparm package.
Usage
Disk info
To get information about your hard disk, run the following:
# hdparm -I /dev/sda
Benchmarking
See Benchmarking/Data storage devices.
Power management configuration
Modern hard drives support numerous power management features, the most common ones are summarized in the following table. See hdparm(8)
for the complete list.
Parameter | Description |
---|---|
-B |
Set the Advanced Power Management feature. Possible values are between 1 and 255, low values mean more aggressive power management and higher values mean better performance. Values from 1 to 127 permit spin-down, whereas values from 128 to 254 do not. A value of 255 completely disables the feature. |
-S |
Set the standby (spindown) timeout for the drive. The timeout specifies how long to wait in idle (with no disk activity) before turning off the motor to save power. The value of 0 disables spindown, the values from 1 to 240 specify multiples of 5 seconds and values from 241 to 251 specify multiples of 30 minutes. |
-M |
Set the Automatic Acoustic Management feature. Most modern hard disk drives have the ability to speed down the head movements to reduce their noise output. The possible value depends on the disk, some disks may not support this feature. |
To query current value, pass the parameter without a value. For example:
# hdparm -B /dev/sda
To apply different value, for example set APM to 127:
# hdparm -B 127 /dev/sda
Tips and tricks
Persistent configuration using udev rule
To make the setting persistent, adapt the following udev rule for your values:
/etc/udev/rules.d/50-hdparm.rules
ACTION=="add", SUBSYSTEM=="block", KERNEL=="sda", RUN+="/usr/bin/hdparm -B 254 -S 0 /dev/sda"
If you have more than one hard drive you could make the rule more flexible. For example, to apply power-saving settings for all external drives (assuming there is only one internal drive, /dev/sda
):
/etc/udev/rules.d/50-hdparm.rules
ACTION=="add|change", KERNEL=="sd[b-z]", ATTR{queue/rotational}=="1", RUN+="/usr/bin/hdparm -B 127 -S 12 /dev/%k"
Putting a drive to sleep directly after boot
A device which is rarely needed can be put to sleep directly at the end of the boot process. This does not work with the above udev rule because it happens too early. In order to issue the command when the boot is completed, just create a systemd service.
/etc/systemd/system/hdparm.service
[Unit] Description=hdparm sleep [Service] Type=oneshot ExecStart=/usr/bin/hdparm -q -S 120 -y /dev/sdb [Install] WantedBy=multi-user.target
Then enable it.
Troubleshooting
APM level reset after suspend
The APM level may get reset after a suspend, so you will probably also have to re-execute the command after each resume. This can be automated with the following systemd unit (adapted from a forum thread):
/etc/systemd/system/apm.service
[Unit] Description=Local system resume actions After=suspend.target hybrid-sleep.target hibernate.target [Service] Type=simple ExecStart=/usr/bin/hdparm -B 254 /dev/sda [Install] WantedBy=sleep.target
Alternatively you can create a hook in /usr/lib/systemd/system-sleep.
Drive is not supported
In this case you could consider using a different approach and the tool hd-idle.