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

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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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221 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 ...
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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
52 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 ...
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116 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
40 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 ...
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1answer
40 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", ...
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4answers
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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 ...
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1answer
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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 ...
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1answer
73 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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55 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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83 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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34 views

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?", ...
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1answer
57 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
31 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 ...
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1answer
64 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
67 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 ...
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1answer
135 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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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 ...
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1answer
7k 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?
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Devices for Analog I/O gone from /dev after reboot

I have a system using Centos 6.6 and another system using RHEL 6.6 on the same architecture that both need analog I/O drivers to communicate with sensors that will be attached to the device. Thus, I ...
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1answer
65 views

Can udev trigger an action upon mount alone?

Can udev be used to trigger an action when an always-connected drive is mounted, or is it only useful for hotplugging (as the documentation suggests)? I want to trigger a script when my ...
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1answer
48 views

Can udev monitor network storage mounting & unmounting?

I want to setup notification whenever any network drive is mounted or unmounted. (Basically I want to run a custom script, whenever any network storage is mounted or unmounted). I think udev can do ...
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2answers
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trigger udev rules from systemd

I have one of those hdds, that have a very aggressive power management. To prevent load cycles from rising in to critical numbers I wrote an udev rule: SUBSYSTEM=="block", SUBSYSTEMS=="scsi", ...
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2answers
455 views

No /dev/hidraw device when I plug in a Yubikey

I have a Yubikey NEO, and I'm trying to get it to work on Debian. When I plug it in, I get udev events, but no /dev/hidraw? device. Here's what I know so far: cat /boot/config-$(uname -r) | grep ...
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57 views

Udev Rule: Auto-increment device number

I have 3 devices which get mounted as /dev/ttyACM[0-2]. Two of these devices are identical, called flow modules. The third is an Arduino Uno. I have the following udev rules which work to a certain ...
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1answer
304 views

udev keyboard remapping with hwdb for secondary keyboards

I have a laptop, and I save the following to /etc/udev/hwdb.d/90-custom-keyboard.hwdb keyboard:usb:v*p* keyboard:dmi:bvn*:bvr*:bd*:svn*:pn*:pvr* KEYBOARD_KEY_1a=a KEYBOARD_KEY_1b=b and run $ ...
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2answers
60 views

Having trouble making sense of the df command

uname -a Linux CentOS01.localdomain 3.10.0-229.14.1.el7.x86_64 #1 SMP Tue Sep 15 15:05:51 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux Here is the output of lsblk on the centos VM I'm playing with: ...
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Thinkpad T61: Udev-rule not working

I'd like to create a special udev-rule to improve the batterylife of my thinkpad T61 by set the brightness to a low value if the power supply is unplugged and my laptop using the battery. Therefore I ...
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76 views

systemd-networkd: Set VLAN device MAC based on host MAC

I am working on a platform with an ARM CPU running linux that has a single MAC in the CPU directly connected to a switch IC. I am trying to set up a VLAN mode using systemd-networkd which I have done ...
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5answers
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How to run long time process on Udev event?

I want to run a ppp connection when my USB modem is connected, so I use this udev rule: ACTION=="add", SUBSYSTEM=="tty", ATTRS{idVendor}=="16d8",\ RUN+="/usr/local/bin/newPPP.sh $env{DEVNAME}" ...
0
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1answer
86 views

USB key does not show up in /dev

We use a USB key system that are contain license files and are provided to unlock proprietary software that we used. The USB drives are small however and get lost easily, so I thought I'd clone them ...
2
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1answer
69 views

udev rule to turn on keyboard backlight

I have a very simple generic gaming keyboard with a backlight. The, typically, universal way to engage the backlight is with xset led 3. I can confirm that this does in-fact work. Because I have two ...
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32 views

Kernel module inconsistency

everyone. I have special USB device (chinese touchscreen), what I need to connect to my computer with Linux. By default, Linux assign connected device to usbhid (I found this info by execute ...
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How to automatically load a new VID&PID to module usb_serial

I have a 4G module that requires me to run echo '03f0 581d' > /sys/bus/usb-serial/drivers/generic/new_id after every startup/resume to make the modem visible. How should I make this automatic? ...
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How can I make udev accept mass storage and reject everything else?

I'm trying to write a udev rule to allow USB mass storage devices but reject anything else (keyboard, mouse, etc). I found this online: ACTION!="add", GOTO="deauthorize_end" SUBSYSTEM!="usb", ...
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1answer
85 views

In udev, what kind of device events match ACTION==“change”?

The udev rules I've created so far only deal with devices being added or removed, i.e.: ACTION=="add"... or ACTION=="remove"... I've come across an example of a rule that seems to deal with device ...
2
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1answer
78 views

Control pseudo-terminal (/dev/pts/*) assignments

Is there any way to control which pseudo-terminal (/dev/pts/*) a connection is given? For example, I have multiple thin clients each running individual terminal sessions to a RHEL server over SSH, I ...
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udev rules official docs

I am looking official UDEV rules, documents, I have noticed there are changes in udev rules in RHEL 7. But could not find any documents some thing like 'request for changes'. Please help Thanks,
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1answer
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What does GROUP in an udev rule actually set?

I have a new Brother MFC and had permission issues and managed to solve them by changing GROUP="scanner" to GROUP="lp" in the relevant udev rule as my user is in the lp group but not in the scanner ...
4
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1answer
150 views

What happened to /dev/raw/?

I am reading an article on LWN and it has an important statement: Raw devices (/dev/raw/rawN) are a special case of O_DIRECT I/O. These devices can be opened without specifying O_DIRECT, but ...
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45 views

udev usb stick device list

We have 2 different yocto distributions: ARM Kernel 3.10.53 X86 SMP Kernel 3.10.0 If we add a USB stick to the ARM system we get different udev messages. usb/usb_device usb/use_interface ...
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Redhat 7.1 Udev Rules changes SYMLINK+ And Name

I am tying to install Oracle ASM on RHEL 7.1, for that trying to configure Udev rules. I have noticed there are is new attribute in udev rules SYMLINK+ which seems to be replacement of NAME ...
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udev rules not working

I am trying to change the name of my network device wlan0 to eth1 in order to get Matlab to active, I have added the file: 70-use-eth1-for-matlab-licensing.rules with the following contents: ...
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1answer
58 views

What are these symlinks in /run/udev/watch?

I searched my computer for all the broken symlinks with the command find / -xtype l And it returned these among a few others: /run/udev/watch/9 /run/udev/watch/8 /run/udev/watch/5 ...
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1answer
1k views

No ttyUSB when connecting USB-RS485 to Beaglebone Black

I'm trying to connect a externally powered board to control the motors of a robot to my BeagleBone Black. I'm using ssh over USB(the mini-usb) to control the Beaglebone from my laptop. The BBB is ...
4
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1answer
103 views

Where is the default device name (e.g. /dev/ttyUSBx) specified?

I'm investigating dynamic device name mapping via udev. The goal: On a multi user system, each user can allocate and free devices like usb-serial converters or PCIe cards (FPGAs). If an user ...
2
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1answer
217 views

udev rules driving me nuts

I have this usb-serial device: root@imx6_armboard:/etc/udev/rules.d# udevadm info -a -p $(udevadm info -q path -n /dev/ttyUSB0) Udevadm info starts with the device specified by the devpath and then ...
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CentOS 7 - Forcing a disk to be /dev/sda

I've been wrestling with this problem for awhile now, and I've hit a wall and need help. In my system, I have 1 drive connected to a SATA port, an SSD. CentOS 7 is installed to this disk. Also in ...