Power on/off USB ports

Is it possible to on/off a specific USB port using the terminal in Ubuntu?

lsusb displays the following result:

Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 2232:1020
Bus 002 Device 009: ID 0bc2:a013 Seagate RSS LLC
Bus 002 Device 003: ID 0a5c:219c Broadcom Corp.

Seagate is my external hard disk drive. Can I power it off in the terminal?

I tried Controlling a USB power supply (on/off) with Linux. But I am confused about what should be replaced in place of usbX.

All of the previous answers talk about a USB suspend mechanism, i.e. a "logical power-off", they will never physically cut the VBUS +5V from the USB port.

Only a few hubs can actually cut VBUS as described here.

The hubpower tool can do it (if the hub supports it).

After running into the same problem, I found that the commands should be entered differently so that "sudo" would apply rights appropriately.

Use the "tee" command.

echo 0 | sudo tee /sys/bus/usb/devices/usb2/power/autosuspend_delay_ms

will apply root rights to the "tee" command which will write the 0 into the specified file, replacing anything that is currently there. To append, use the tee command with option -a.

for info see the man page of tee

Actually usbX is nothing but the USB ports numbers where X denotes the number like 1 or 2 and so on... For example, usb1 and usb2 for ports 1 and 2. In general, a laptop may have three or four USB ports with USB 2.0 and USB 3.0 ports.

In Ubuntu, usb1, usb2...usbX are the links to /sys/devices/pci000:00/*. To understand it well, run this command:

ls -l /sys/bus/usb/devices/

So to enable/disable USB ports usbX will be replaced with usb1 when you want to enable/disable USB Port Number 1 (or refer Stack Exchange):

Edit: Thanks to Stefan Denchev to tell the correct way to echo some text to a file using sudo. (Check his comment also.) You should not get the permission denied message now.

sudo sh -c "echo '0' > /sys/bus/usb/devices/usb1/power/autosuspend_delay_ms"
sudo sh -c "echo 'auto' > /sys/bus/usb/devices/usb1/power/control"

After seeing your lsusb result, it looks like your Seagate device is connected to Port No. 2, so you need to disable usb2. Then the commands would be:

sudo sh -c "echo '0' > /sys/bus/usb/devices/usb2/power/autosuspend_delay_ms"
sudo sh -c "echo 'auto' > /sys/bus/usb/devices/usb2/power/control"

udisksctl has power-off flag, which I suggest you use in conjunction with unmount

From the man udisksctl:

power-off
           Arranges for the drive to be safely removed and powered off. On the
           OS side this includes ensuring that no process is using the drive,
           then requesting that in-flight buffers and caches are committed to
           stable storage. The exact steps for powering off the drive depends
           on the drive itself and the interconnect used. For drives connected
           through USB, the effect is that the USB device will be deconfigured
           followed by disabling the upstream hub port it is connected to

Demo

Here's me unmounting my USB jumpdrive and then powering it off

testdir:$ lsusb
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 009: ID 154b:007a PNY 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

testdir:$ lsblk                                                                
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 111.8G  0 disk 
└─sda1   8:1    0 111.8G  0 part /
sdb      8:16   1    30G  0 disk 
└─sdb1   8:17   1    30G  0 part /media/xieerqi/6A32C4555E1C5B4D
sr0     11:0    1  1024M  0 rom  

testdir:$ udisksctl unmount -b /dev/sdb1 && udisksctl power-off -b /dev/sdb1
Unmounted /dev/sdb1.

testdir:$ lsusb
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

testdir:$ lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 111.8G  0 disk 
└─sda1   8:1    0 111.8G  0 part /
sr0     11:0    1  1024M  0 rom  

testdir:$