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

learn more… | top users | synonyms

66
votes
5answers
96k views

How to reload udev rules without reboot?

How should one reload udev rules, so that newly created one can function? I'm running Arch Linux, and I don't have a udevstart command here. Also checked /etc/rc.d, no udev service there.
38
votes
4answers
5k views

Why are network interfaces not in /dev like other devices?

I'm mostly curious, but why aren't network interfaces in /dev? Are there any other kinds of devices that aren't represented as a node under /dev?
35
votes
6answers
13k views

How can I detect when a monitor is plugged in or unplugged?

Is there any event that is triggered when I plug in or out an external monitor into the DisplayPort of my laptop? ACPID and UDEV don't react at all. I'm using onboard graphics on an intel chip. Here ...
32
votes
11answers
12k 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 ...
27
votes
3answers
5k views

Why do some Linux distributions still have /dev/ttyS0, ttyS1, etc., even though newer computers don't have such a serial port?

Many new laptop and desktop computers do not have 9-pin/25-pin serial ports. Why do many Linux distributions still contain /dev/ttyS0, dev/ttyS1 device files? Since udev can create the device files ...
22
votes
2answers
23k views

How to run custom scripts upon USB device plug-in?

What is the state-of-the-art method for automatically executing custom scripts upon USB device plug-in under current Linux distributions like Debian/CentOS/Fedora? For example if you want to ...
21
votes
1answer
16k views

How to assign USB driver to device

This question is two-fold: First, how do you manually detach a driver from a USB device and attach a different one? For example, I have a device that when connected automatically uses the ...
15
votes
2answers
34k views

How can I find available network interfaces?

This is in regard to linux, but if anyone knows of a general *nix method that would be good. I booted a system yesterday with an ethernet cable plugged in. "NetworkManager" is not installed, so once ...
13
votes
5answers
3k views

Difference between sdX and vdX

When I use Ubuntu and CentOS, I see /dev/sda and /dev/vda. So I can't understand what is the different between above two?
13
votes
2answers
10k views

In which log should I check for udev errors?

I've written a udev rule which is run each time my device is mounted/dismounted. However, in which Linux (Debian) error log should I check when debugging such rules?
11
votes
3answers
1k views

Are there alternatives to using `udev`?

While I understand the greatness of udev and appreciate the developers' effort, I was simply wondering if there is an alternative to it. For instance, I might imagine there should be a way to make ...
10
votes
1answer
8k views

Understand output of `udevadm info -a -n /dev/sdb`

I plug an external HDD into my laptop. I try to find out the information by $ udevadm info -a -n /dev/sdb Udevadm info starts with the device specified by the devpath and then walks up the chain of ...
9
votes
1answer
4k views

Difference between /dev and /sys/class?

What is the difference between the device representation in /dev between the one in /sys/class? Is one prefered over the other? Is there something one offers and the other doesn't?
9
votes
2answers
782 views

What's the difference between udev and hald?

I'm just beginning to dive into the internals of Linux, and I was wondering what the difference is between udev and the hal daemon. From what I gather, both seem to be responsible for managing hot ...
9
votes
3answers
2k views

Fake serial number of USB device

I have a mobile phone connected to my PC via USB. When viewing the device info using sudo udevadm info --attribute-walk the product and vendor id's show up fine, but there is no ATTR{serial}. An ...
8
votes
1answer
799 views

reference whole disk (/dev/sda) using UUID

On my system (Debian), I can see the UUID identifier for all of my disks partitions (i.e. /dev/sda1, dev/sda2, ..) ls /dev/disk/by-uuid/ However, I don't see the UUID identifier for /dev/sda ...
8
votes
1answer
2k views

What is the correct way to write a udev rule to stop a service under systemd

I'm running Arch Linux, and I have a udev rule which starts a service when a device is inserted. In this case, it dials a connection when a 3G modem is plugged in. KERNEL=="ttyUSB*", ...
8
votes
3answers
1k views

How to enable “Predictable Network Interface Names”?

I decided to check out what name my ethernet device will end up with, but contrary to other distros, Debian doesn't seem to have activated this change (or is holding it back?), * Keep the old ...
7
votes
2answers
3k views

How can I hide messages of udev?

When I plug in a usbhub (7 sticks in) udev displays a lot of messages in console. Can I hide these messages or send them to /dev/null?
7
votes
3answers
3k views

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?
7
votes
2answers
2k views

mknod permanent in archlinux

I have a custom kernel module (on ArchLinux) that I can load manually and interact with. What I would like to do is have it loaded at boot time. So far I have managed to get the device appear in ...
7
votes
1answer
2k views

USB connect/disconnect notification

I use Linux Mint 13 MATE, and I'm trying to set up notifications when I plug/unplug devices. First of all, I found udev-notify package, but unfortunately it almost doesn't work for me: it works for ...
7
votes
2answers
2k views

udev rule for assigning known symlinks for identical usb serial devices

I have two (and possibly in the future, more) USB serial devices which are identical (down to the serial number, unfortunately) - they're actually BTC miners. Currently they end up as ttyUSBX where X ...
7
votes
3answers
22k views

Udev : renaming my network interface

I just installed RHEL 6.3 on a Dell 1950 server. This server as two GBit ports, Gb0 and Gb1. For some obscure reason, udev chose to name Gb0 eth1 and Gb1 eth0. This is definitly not a good find for ...
7
votes
2answers
2k views

Auto-run script when Wifi card is plugged in (udev)

I've been trying to use udev to make a Debian system run a bash script when a wireless card is connected. So far I created this file /etc/udev/rules.d/wifi-detect.rules: ACTION=="add", ...
7
votes
2answers
2k views

Making UDEV ignore certain devices during boot.

I'm trying to make UDEV stop mounting one of my devices at boot time, and I've created a rule in /etc/udev/rules.d/ called 1-myblacklist.rules. All the rule does is matches the device by kernel ...
7
votes
2answers
1k views

Suggestions needed for udev, udisks, autofs, notification setup for a complete automounting solution on Linux

Continuing on Automounting plugged devices in linux, which left things a bit basic. Running Gentoo, I'm automounting a combination of local and network devices on my laptop with autofs-5.0.4-r5. Doing ...
7
votes
2answers
996 views

How can I change the permissions in /sys to alter the state of a LED/light using `udev`?

I've got a Thinkpad and would like to use the ThinkLight (the white flash light above the screen designed to light up the keyboard) for notifications on incoming Jabber messages. It is easy to ...
6
votes
2answers
237 views

/dev/disk/ lists disks, why /dev/net/ doesn't list network interfaces? [duplicate]

I know that udev manages devices in /dev and I expected to find information about available network cards (hardware) or at least network interfaces (software) there. ifconfig output shows me eth0 and ...
6
votes
1answer
439 views

how to find out if kernel or udev created a device node?

Is there any way to find out who created a device node? If it has been udev or the kernel itself? In the specific case of mine, I have two webcams. Nodes created for them are /dev/video0 and ...
6
votes
1answer
6k views

Why doesn't this udev rule trigger upon removal of the device?

I have two mice, one which has an issue where the middle mouse button and button6 get triggered simultaneously. So I configured my ~/.Xmodmap to disable this button. At the same time, however, I ...
6
votes
3answers
68 views

different passwords depending on plugged-in devices

I would like to have different passwords for my account(s): When (e.g.) a certain USB stick is plugged in then an easy password is to be used. The idea is: If I leave my computer then I take the stick ...
6
votes
1answer
523 views

Swapping <esc> and <caps lock> in a way that persists with external keyboards

I have a file called ~/.speedswapper which contains the following: ! Swap caps lock and escape remove Lock = Caps_Lock keysym Escape = Caps_Lock keysym Caps_Lock = Escape add Lock = Caps_Lock ...
6
votes
1answer
563 views

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", ...
5
votes
4answers
15k views

Automounting USB sticks on Debian

I'm running Debian Squeeze on a plug computer (so SSH only, no GUI) and what I'm trying to do is get it so that when a USB stick is plugged in, it gets automatically mounted. What I've done is ...
5
votes
3answers
3k 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' ...
5
votes
3answers
6k views

How can I create a udev rule to mount a USB drive read only?

I'm trying to set a particular USB drive to always mount read only. If I plug it in, it is seen as sdb with a single partition, sdb1. Here are some relevant udevadm lines (not the entire output of ...
5
votes
3answers
2k views

Watch USB connections vendor id, product id, revision

I'd like to simply watch all devices added and removed from my system and view their USB vendor ID, product ID, and revision and other relevant information. How can I do this in Linux? Is there a ...
5
votes
2answers
4k views

Permanently changing the ownership (or group) of LVM volume

How can I permanently change the ownership (or at least the group) of a LVM volume? I figured that I have to use udev, but I don't know how the rule should look like? Let's say I want to change the ...
5
votes
2answers
18k views

Cloned Linux system and /etc/udev/rules.d/70-persistent-net.rules

I set up an Ubuntu system and configured it properly, including defining eth0 in /etc/network/interfaces. I then imaged that system and cloned it on a new system. When I booted up the system the ...
5
votes
2answers
4k views

/dev/hidraw: read permissions

What do I need to do to have read permissions on /dev/hidraw*? I'm seeing stuff about udev rules and saw this on the net, but the world of udev is like a foreign land to me, and if there's some sort ...
5
votes
2answers
4k views

Network naming on Arch Linux

I've just installed Arch Linux on my old PC, to do the installation I used wifi-menu wlan0, now I've reboot but if I type: ifconfig wlan0 up I have as a result: wlan0: ERROR while getting ...
5
votes
1answer
3k views

Udev rule is not being used?

I'm setting up udev to handle my external USB hard drive when it gets plugged in and removed (no mounting yet). So far, I've made two new rules in /etc/udev/rules.d/10-local.rules to log ...
5
votes
2answers
136 views

Where to install local software that runs before /usr is available?

I'm writing a local program to be called by a udev IMPORT{program} rule. Normally, I'd install local software in /usr/local, but these udev rules are run when block devices appear. So they're running ...
5
votes
1answer
570 views

List all udev rules (e.g. for a device)?

I want to know how I can list all udev rules. I know that in they can be potentially stored as lines (one line = one rule) in *.rules files in these directories /etc/udev/rules.d /lib/udev/rules.d ...
5
votes
5answers
17k views

Ubuntu 13.04 does not recognize USB drive

Using Ubuntu 13.04 (with Gnome 3), my new USB stick (details see dmesg/lsusb) doesn't show up automatically. Situation: The drive does not show up at fdisk -l The drive does appear when running ...
5
votes
4answers
3k views

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}" ...
5
votes
1answer
2k views

How do I disable udevd in systemd?

I'm trying to boot a Fedora Rawhide LXC container from a Fedora 16 host, and it's not working - systemd just keeps dropping into emergency mode. Because udevd doesn't work in LXC containers, I thought ...
5
votes
1answer
1k views

Problems copying large files to USB drive

I've got some issues when copying larger files to my USB drive. First of all, my system stopped recognizing my USB drives automatically. I now have to run modprobe usb-storage in order for my USB ...
5
votes
2answers
108 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 ...