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Questions tagged [usb]

USB is an acronym for Universal Serial Bus. The current USB standard is USB 3.0, which supports transfer speeds of up to 625 MB/s. USB devices are plug-and-play.

USB supports plug and play, which means that the operating system takes care of allocating system resources. The current maximum length of a USB cable can be about 5 metres, but it can be increased using a repeater cable.

While the Linux kernel contains a wide variety of device drivers, in some cases devices may not work right out of the box with Ubuntu and additional drivers need to be installed.

Wikipedia has more detailed information about the USB standard, covering:

  • Version history, including upcoming versions
  • Device classes
  • Connectors, plugs and cables
  • Power distribution
  • Signaling
  • Related and competing standards like Thunderbolt

Universal Serial Bus (USB) is an industry standard [...] that defines the cables, connectors and communications protocols used in a bus for connection, communication, and power supply between computers and electronic devices. [...]

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USB turn write protection off

I have a USB which is write protected: dmesg | tail [10098.126089] sd 7:0:0:0: [sdb] Write Protect is on [10098.126098] sd 7:0:0:0: [sdb] Mode Sense: 23 00 80 00 [10098.126779] sd 7:0:0:0: [sdb] No Caching mode page present [10098.126788] sd…
noob
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How do I find out whether my system has USB 3.0 ports?

I want to buy an external USB 3.0 drive and I wonder how to figure out whether my laptop has such a port (or only 2.0). Neither lsusb -v, nor /proc/bus/input/devices offers any obvious hints, although the former says a lot of 2.0 root hub which…
sds
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Copy to USB memory stick really slow?

When I copy files to the USB device, it takes much longer than in windows (same usb device, same port) it's faster than USB 1.0 speeds (1MB/s) but much slower than USB 2.0 speeds (12MB/s). To copy 1.8GB takes me over 10 minutes (it should be < 3…
Eloff
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How to detect an USB device?

I got a scenario, where a software works only when you insert the USB device provided by the software vendor in windows operating system. Im trying to find the content stored in the USB device. In windows operating system, the USB device icon is not…
Learner
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lsusb command not found

I've installed Ubuntu on an external drive and it don't see my USB dongle. I am a complete novice with things Ubuntu. After doing some digging I found that step 1 was to run lsusb. But that set of instructions doesn't say what to do it lsusb…
fernny500
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External USB hard drives - what speeds should be expected?

Given the number of questions ive seen about slow usb transfer speeds I have to wonder what speeds should one be expecting for a 'typical' usb2 and usb3 hard drives? A side question would be what would be considered a proper way to test these…
dr_willis
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Is it possible to turn off a specific USB port so it doesn't accept any device?

I have a lot of ports on my computer. I would like to turn off one of them, so when I connect my phone to that port, it only charges. I do want my phone to work with my computer in some occasions though, so I hope other ports are not affected. I…
bfrguci
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Running a script when connecting a USB device

I am trying to run a script whenever a pendrive is connected to my system. I followed this and this question and it is working, but there are still some problems. This is my udev rules file: ACTION=="add", ATTRS{idVendor}=="8564",…
Null pointer
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How to switch off caching for usb device when writing to it?

I have problems transferring binary programs to a micro-controller prototype board when using ubuntu/kubuntu to mount the board via usb. With MacOS and Windows there are no problems. I have found the writing from Ubuntu definitely changes the…
txwikinger
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I can't find a file I moved to USB drive

I downloaded a short video, then wrote: sudo mv /home/myname/Downloads/m.mp4 /dev/sdb1 the video disappeared completely. It's not in the USB drive. I searched for it by writing: find / m.mp4 find m.mp4 But it's nowhere to be found.I keep…
Amasa Levi
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4 answers

USB stick detected but can't be mounted

I have a Kingston DataTraveler SE6 8GB USB stick which I use as a liveusb medium. The liveusb was created with UNetbootin and was working fine, I also enabled persistance in it. Today I connected the USB into another computer but it was not being…
Uri Herrera
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4 answers

USB Getting *Cannot enable. Maybe the USB cable is bad?* error with multiple devices, but only sometimes

I'm using Ubuntu 20.04, installed it an year ago and haven't had any problems until now. Now, when I start the computer, everything works fine related to the USB ports, but after a bit of time one of the ports stops working, and after a bit more…
H-005
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Why don't Etron USB 3.0 controllers/ports work? (Asus P8Z68-V and other motherboards)

I have a new computer with an Asus p8z68-v le + Intel 2500 + 8GB of RAM. I installed Ubuntu without any issue but the USB3 (from the mother board - on the back of the computer) don't work. I plug a USB stick noting, I plug my USB3 external drive…
Adéline
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Where is my keyboard, mouse and other HCI devices mounted in linux?

i have heard that everything in linux is treated as files.. i was just curious as to where would i find to explore the usb mounted on my machine (HCI dev)
juggernauthk108
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Share USB drive over network

I'm looking for a free method to share an USB device over network. I got a RaspberryPi (raspbian) which has an USB device connected. I want to be able to receive and send command to this device from my Linux server. I tried remserial but I'm unable…
PyNico
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