Udev is a Linux process that manages device file entries under /dev

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What is this dd if=/dev/zero of=/dev/sda do

Could someone help me understand what I got? dd if=/dev/zero of=/dev/sda bs=4096 count=4096 Q: Why specifically 4096 for count? dd if=/dev/zero of=/dev/sda bs=512 count=4096 seek=$(expr blockdev --...
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2answers
81 views

Fn keyboard keys not working (when udev is disabled)

I am in the process of getting rid of udev daemon from my system. I have fixed all issues, only one small problem is remaining: It used to be (when I was using udev), that Fn+Down acted as ...
2
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1answer
109 views

setting up Xorg input devices without udev

I have udev support in kernel(CONFIG_DEVTMPFS), thus my system does not strictly require udev daemon. Indeed everything works fine without udev daemon with the exception of Xorg (LXDE). LXDE starts ...
37
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11answers
17k views

A tool for automatically applying RandR configuration when external display is plugged in

is there a tool which enables one to: remember current RandR configuration (position, orientation, resolution etc) on per-monitor basis, automatically apply last known good configuration as soon as ...
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0answers
29 views

What is the difference in using xinput and synclient for deactivating a touchpad in X

I have troubles using xinput --disable or --set-prop "Device Enabled" or set-prop "Synaptics Off". It seems that --disable / --enable and "Device Enabled" are meant to deactivate the whole device, ...
3
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1answer
95 views

ALSA - Traktor Audio 2 - How to split front and rear stereo channels / How to debug dmix

I am struggling to persuade ALSA to separate the front and rear outputs of my Native Instruments Traktor Audio 2 external USB soundcard and would really appreciate help. USB Vendor ID: 17cc, USB ...
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1answer
12 views

Udev rules matching a command's output (or something similar)

I'm writing a common udev rule for deployment to computers with one or two Silicon Motion SM501 video cards installed. This is the current rule: TAG=="seat", ENV{ID_FOR_SEAT}=="usb-pci-*-usb-*_[34]", ...
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1answer
73 views

How do I connect a USB mass storage device that has a custom pid and vid?

I have a device, custom mp3 player, that the pid and vid show up as a011:a011. dmesg usb 1-1.1: new high-speed USB device number 4 using ehci-pci usb 1-1.1: New USB device found, idVendor=a011, ...
0
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1answer
50 views

Is it possible to get the devtype of a USB wifi device?

I know udevadm info gives the devtype of disks as disk. However, how would I get the devtype of a usb wifi adapter? (ie wlan, wwan, etc)
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0answers
30 views

Dynamic mdev ifup and ifdown of network interface

Is it possible to have an mdev.conf rule that would run ifup on device creation and ifdown on detach? i.e. eth[0-9] root:root 660 @ifup $MDEV | $ifdown $MDEV
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0answers
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udev working with SYMLINK but not with NAME [duplicate]

Problem: I'm writing persistent naming rules for a USB dongle following the tutorial here. The rule works as expected for : SUBSYSTEM=="tty", ATTRS{idVendor}=="0658", ATTRS{idProduct}=="0200", ...
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1answer
25 views

Writing to /dev/kmsg with udev run

I have written a simple udev rule to name my usb device: SUBSYSTEM=="tty", ATTRS{idVendor}=="0658", ATTRS{idProduct}=="0200", SYMLINK+="ttyUSB-ZStick-5G" udev offers ways to run custom scripts on ...
0
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1answer
58 views

How can I permanently change the ownership of a mounted device under `/media/$USER`?

I'm using an encrypted (cryptsetup with LUKS with ext3) SD-Card as disk space extension. When entering the key in Nautilus, the device is decrypted (/dev/dm-3) and mounted in /media/$USER/. ...
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2answers
55 views

How to skip boot time custom udev rule?

I have following udev rule in /etc/udev/rules.d/80-foo_usb.rules to detect pen drives, KERNEL=="[a-z][a-z][a-z][1-9]", SUBSYSTEM=="block", ACTION=="add", PROGRAM+="/test/foo.sh $kernel $parent" It ...
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0answers
25 views

Udev: cmd executed when attaching device, but does nothing

I created rules which should run a command when i attach my USB mouse to disable the touchpad and the point stick: machine ~ # cat /etc/udev/rules.d/61-touchpad.rules # 61-touchpad.rules # disable ...
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4answers
7k views

Get device node by major/minor numbers pair

Each device node under /dev has its own major/minor number pair. I know that we can retrieve this pair of numbers from the device node by means of stat, like this: stat -c 'major: %t minor: %T' <...
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0answers
33 views

How to wait for detected LVM volumes?

I have the following problem: I have a machine running arch and which contains a encrypted LV in a LVM. Inside the (encrypted) LV is another PV located. So I have in fact two VGs: One which contains ...
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0answers
15 views

Cant interactive external program be executed using udev rules? [duplicate]

I am using following udev rule(s) to execute my program whenever block device (e.g. USB) will be attached. ACTION=="add", SUBSYSTEM=="block", PROGRAM+="/tmp/foo %k" or ACTION=="add", SUBSYSTEM=="...
0
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1answer
85 views

What's the difference between udev and acpi(d)

They both seem to be receiving & processing kernel events, so why do they both exist? From what I gather, ACPI seems to be more high-level compared to udev, but apart from that can't really tell. ...
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1answer
35 views

USB LABEL in different language

If the USB LABEL (name) is in different langauage (Hindi or Chinese) how do i get to know which language it is coded to pass to the iconv or is there any way we can know the language which has been ...
0
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2answers
30 views

Program run from udev cannot open a window [duplicate]

I have a script, written in python: #!/usr/bin/python3 from tkinter import messagebox variable = messagebox.showinfo('title', 'question') This python script does nothing else than showing a message ...
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0answers
45 views

Scripts timeout using USBMount

I'm using Usbmount (https://github.com/rbrito/usbmount) on a raspbian system to auto-detect the insertion and removal of a usb stick in to the unit and then run a script from the /etc/usbmount/mount.d/...
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2answers
111 views

UDEV executes bash script only partially

I have this UDEV rule, which gets activated when I plug in my keyboard: ACTION=="add", DEVPATH=="/devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1:1.0/0003:046A:0011.00??/input/input??/event[0-9][0-9]*", ...
4
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1answer
103 views

How does linux load firmeware for built-in driver modules

I've learned that the firmware-subsystem uses udevd to copy a firmware to the created sysfs 'data' entry. But how does this work in case of a built-in driver module where udevd hasn't started yet? I'...
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1answer
1k views

Udev rule: ACTION==“add” is working, but ACTION==“remove” isn't working!

I've written file 90-usb.rules under /etc/udev/rules.d/ containing: ACTION=="add", ATTR{idVendor}=="0bb4", ATTR{idProduct}=="2008", RUN+="/bin/mkdir /home/pandya/Desktop/testdir" ACTION=="remove", ...
1
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1answer
34 views

How to change keyboard settings of the active user using udev and setxkbmap?

I have a usb keyboard that I plug in into my desktop at work. While using it tend to manually set the following setxkbmap option: setxkbmap -option compose:ralt setxkbmap -option ctrl:swap_rwin_rctl ...
5
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2answers
516 views

how to write a udev rule to remove a tag?

Is it possible to write a new udev rule that undoes TAG+="uaccess" (removes the uaccess tag) without undoing any of the other tags on a device? If so, how? (I have a device that should be opened by ...
8
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1answer
200 views

Need help improving my Bash script

I need some help improving my Bash script so that it runs flawlessly without having issues. This script uses ds4drv in it and it has some issues that I'm unsure on how to correct. First issue is that ...
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0answers
23 views

how do I add a udev property for my android phone?

I'm trying to get my android phone recognised by rhythmbox. Talking to upstream, rhythmbox gets the value of "id_model" for the udev device - if it is "Android" then it should work. How do I use a ...
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3answers
2k views

How to debug an udev rule (in /etc/udev/rules.d/…)

I'm creating a new basic rule /etc/udev/rules.d/10-myrule.rules containing: KERNEL!="sdb*", GOTO="auto_mount_end" ACTION=="add", RUN+="/usr/bin/mount /dev/sdb1 /media" LABEL="auto_mount_end" I ...
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1answer
272 views

Dependency failed for mount after dist-upgrade

Last weekend, I ran an apt-get dist-upgrade on a home Debian 8.3 system, and was surprised to see that it entered emergency mode on the next boot. The server in question runs LVM on top of a mdadm ...
11
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3answers
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Udev- How do I find out which subsystem a device belongs to?

For example, I have device /dev/sdb. How do I find out it's udev subsystem?
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1answer
63 views

How is /dev/null created on archlinux

Just wondering how is /dev/null created on my archlinux box. I investigated udev rules under /usr/lib/udev/rules.d, but there are no rules relating to to name null. > ag null /usr/lib/udev/rules....
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0answers
152 views

Setting standby timeout with hdparm during boot via udev rule not working

I set the APM level and standby timeout of my HDDs during boot with a udev rule: ACTION=="add|change", KERNEL=="sd[b-z]", ATTR{queue/rotational}=="1", RUN+="/usr/bin/hdparm -B 63 -S 36 /dev/%k" I ...
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2answers
69 views

What causes a PCI ID to change

When running lspci on my RHEL 7.2 box I noticed my Ethernet Adapters changed PCI bus IDs. In the example below it changed from "02:00.x" to "03:00.x". What might have caused this? Is there a way ...
0
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1answer
52 views

Using udev rules to let everyone set ip address to a network interface

I want to let everyone on the system to be able to change the ip address of a network interface. I have wrote a rule in /etc/udev/rules.d like this: SUBSYSTEM=="net", ATTR{address}="00:0c:26:c6:70:93"...
3
votes
4answers
4k views

udev re-numbering when creating symlinks

I have USB cellular modem attached to an ALIX 3d2 board running voyage linux (which is based on Debian Squeeze). The modem registers itself as a TTY device, and so by default, udev will create TTY ...
6
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1answer
3k views

How to regenerate 70-persistent-net.rules without reboot?

The file /etc/udev/rules.d/70-persistent-net.rules is auto-generated on a Linux system with udev, if it does not exist during reboot. But I would like to know a command how to create this rules file ...
1
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1answer
84 views

udev creates the right rules, but rights disappear as soon as I try to access files via C++

I'm facing a really strange problem using udev. As I already explained here I'm trying to access some folders/files as a no root user Here are my udev rules for the gpio folder: KERNEL=="gpio*", ...
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0answers
70 views

Cannot install GPIO on CubieTruck : Error processing udev archive

I am running Cubieez 2.0 on a Cubietruck. After running apt-get update, I wanted to run pySUNXI GPIO. However, I encountered a problem: root@cubietruck: cd pySUNXI-VSRNDCT-0.0.1/ python setup.py ...
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1answer
130 views

udev disk mount permissions in linux

We would like to set up a customer account on our overo running embedded Angstrom along with ssh so they can log on to retrieve data. uname -a Linux pb014-01 2.6.32 #1 Wed Feb 29 15:17:02 GMT 2012 ...
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1answer
3k views

“PS/2 Generic Mouse” gets lost. How to reload without reboot?

I am running Ubuntu 12.04LTS on a ThinkPad E420s. My Trackpoint is recognized as "PS/2 Generic Mouse". My problem is that it doesn't load/disappears after booting or after suspension. I can't move ...
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0answers
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udev: Wrong symlink is made at boot time

I am trying to create a udev rule to give a static name to a ttyUSB (a FTDI USB serial cable). My rule is quite simple (the file is named 99-usb-serial.rules): KERNEL=="ttyUSB?", ATTRS{serial}==...
0
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1answer
66 views

udev doesn't apply changes recursively

I'm working with a beaglebone black board (ubuntu release for ARM architecture), which has some general purpose input/output (GPIO) interface to read sensors/drive motors etc.. which are configurable ...
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1answer
39 views

How do I automatically force a umount on a usb drive that has already been removed?

I have debian system that auto mounts an entry in my fstab file when a usb drive is connected. This is done so as a read only device The device is mounted to /media/usb1 If i'm in the console and ...
2
votes
1answer
78 views

How to disable asking for root password while ejecting USB drives?

When I mount usb drive it mounts successfully, but when I hit triangle button in Thunar (Eject) - I'm asked for root password! Executing $ udisks --eject /dev/sdd in console doesn't require root ...
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1answer
86 views

Why is my udev rule executed three times

I've made a little udev rule that launch a script that make an archive of my ~/Documents directory. That do the job, but when I read the log file, it seems that the archive script is executed 3 times ...
3
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1answer
216 views

change size of devtmpfs /dev/

My new kernel has CONFIG_DEVTMPFS enabled, and thus my /dev is mounted as devtmpfs. My old kernel was not using CONFIG_DEVTMPFS, and /dev used to be mounted as plain tmpfs. Now I have noticed, the ...
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0answers
139 views

when running `udevadm test`: `no db file to read /run/udev/data/+gpio_sw:PA7: No such file or directory`

I am trying to write an udev rule that matches a GPIO Pin of my Orange Pi (the GPIOs use the gpio-sunxi kernel module). My ultimate goal is to let users who are member of a particular group access ...
16
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1answer
8k views

Difference between /dev and /sys/class?

What is the difference between the device representation in /dev and the one in /sys/class? Is one preferred over the other? Is there something one offers and the other doesn't?