The Linux/Unix /dev directory contains the special device files for all the devices.

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dd aplied to dev USB before connect corrupt /dev/sdX and dont work

I have a USB where I'm coping an ISO of 5 Mb aprox with a small OS with its own grub. If I connect the device and check it sudo fdisk -l I get: ... Device Boot Start End Sectors Size Id Type /...
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How to Access `/dev` From Inside a `chroot` Jail?

     How can one access /dev from within a chroot jail? I'd like to know how to do this on OS X v10.11.5 'El Capitan,' in particular. I've already tried to create an ...
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18 views

Attached devices change /dev/sd value

I have a script which auto mounts my Windows partition based on UUID, reason: my attached devices change their /dev/sd value. After booting up, my external hard drive might take on /dev/sda or /dev/...
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How can I get a Git repo to push/pull when the Git server is behind a firewall?

My work place currently has a gitlab server behind their corporate firewall and currently their public dev sites are facing the internet. I can access the gitlab server only when I'm on their vpn. I ...
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21 views

Files in /dev below devtmpfs mount

I noticed on some Linux systems, that there are actual files on the root partition in /dev in unmounted state. These will be covered by the devtmpfs mount once established, which usually happens quite ...
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Detecting new USB devices with bash?

I'm writing a bash script that needs to detect when a usb storage device is inserted and assign it to a variable that would otherwise, typically look something like: usb=/dev/sdb. I have a few ...
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28 views

How can I set device mode via networkd

How can I set mode to device (for example monitor/ap to wlan) via networkd deamon in .link file ??? Because I want to set bridge in .network of wlan device and I can't do it until I set it in ...
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98 views

v4l2 Identifying /dev/video* via lsusb

I'm writing a script that must use a particular camera plugged in to my system. $ lsusb|grep C930e Bus 001 Device 011: ID 046d:0843 Logitech, Inc. Webcam C930e How can one programatically discover ...
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creating linux device files for bootstrap

I'm currently independently researching device files as a part of learning more about the Linux system in depth. My current goal is to bootstrap Debian Linux through cdebootstrap. I followed the guide ...
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72 views

rsyslog.conf: kern.err /dev/console. Where do these messages go?

There is a commented line in rsyslog.conf: #kern.* /dev/console If I add this line to the configuration file: kern.notice /dev/console Where do these messages go? If I run this ...
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113 views

Why do loop devices sometimes refuse to go away?

I regularly mount the partitions inside an image file as loop devices: sudo kpartx -a test.img That creates loop devices such as /dev/mapper/loop0p1 /dev/mapper/loop0p2 When I'm done, I get rid ...
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Can the contents of /dev/disk0 (/dev/sda, etc) be used as stdin?

I'm learning about the /dev filesystem. I've begun with /dev/sd* (Linux) and /dev/disk* (OS X), and I've found some interesting behaviour. If I run: $ sudo xxd -l 1024 /dev/disk0 I get the ...
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cp file in /dev/sdc, now drive isn't readable

So I was trying to instal Arch on my Laptop, and I wanted to copy boot.efi into my usb. cp boot.efi /dev/sdc cp boot.efi /dev/sdc1 cp boot.efi /dev/sdc2 and now its not being read. How can I fix my ...
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242 views

Not quite grasping /dev/random and /dev/urandom

I am not quite understanding the difference between /dev/random and /dev/urandom on Linux systems. What does it mean to run out of “entropy” and how does the system get more? What does it mean when ...
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How is by-id created on Linux?

Sticking a USB-microcontroller on the port (similar to Arduino) creates these two files: /dev/serial/by-id/usb-MBED_MBED_CMSIS-DAP_10105a42e87da33c103dccfb6bc235360a97-if01 /dev/disk/by-id/usb-...
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33 views

Drive assignments changing

I have an Ubuntu 14.04 Server machine set up with 3 drives: Two 2TB HDDs, and a 4GB USB drive for system. It seems that every time I boot the system it changes what drives are assigned to /dev/sd(a/b/...
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621 views

Micro SD impossible to modify (write or format)

Recently i had problems with my SD card used for my android device, basically i cannot modify it (write or format). Only read it, if i try format or write, any time that connect and fisconnect from ...
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54 views

Cat to /dev/audio not working

I downloaded some files and am trying to cat them to /dev/audio (for fun of course, I'm sure I could just play them) and I guess this is supposed to work, but it doesn't? I get permission denied and ...
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481 views

Can't mount external HDD. Device listed at lsusb but doesn't appear at /dev

Device works at Windows but doesn't appear at /dev. How can I mount it? So let's go to the infos... uname -a: Linux deeptought 3.13.0-30-generic #54-Ubuntu SMP Mon Jun 9 22:45:01 UTC 2014 x86_64 ...
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/dev/dsp missing in debian and cannot hear festival utterance

Tried to make an utterance in festival and it seems /dev/dsp/ is missing in the debian. How to add this? festival> (SayText "Hello") Linux: can't open /dev/dsp #<Utterance 0xb669c708>
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104 views

Can't recongnize my SSD device file in /dev

I am using Ubuntu and can't find my SSD device file. The /dev directory has following contents: agpgart audio audio1 audio2 audio3 audioctl char console core dsp dsp1 dsp2 dsp3 fd full kmem kmsg log ...
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138 views

Why does the /dev directory exist?

In Linux, there is the /dev directory, which is a special directory which contains all of the files for devices and other things like random, urandom, etc. Why did this directory exist? Was it just ...
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173 views

Does unplugging a disk from linux change disk name after restart?

I had 5 disks (sda, sdb, sdc, sdd, sde) sda is being used for root and boot. sdc,sdd and sde disks are being used by lvm. We unmounted and unplugged the sdb, now I need to restart the server. I am ...
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278 views

Hauppauge HD PVR 2 to ffmpeg on OS X

How can I use ffmpeg to capture video and audio from a Hauppauge HD PVR 2 connected to my Mac via USB? I have seen a couple posts here and here about doing this on a Unix machine (not OS X) using ...
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834 views

Disable device node using udev (/dev/sr0)

I am trying to disable udev from generating /dev/sr0 device (my cdrom) and Im trying to write udev rules. I added a file 10-cd-trial.rules in /etc/udev/rules.d and /lib/udev/rules.d, the contents are:...
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Partition Not Showing up in /dev

I recently unmounted a 4TB hard drive from one computer in order to access the files directly from another computer. It seemed like there were no problems with the unmounting process. When ...
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How to move /dev/random to another drive on a server

We found a bottleneck in our server (hosted on HDD) related to the /dev/random function. We want to have the OS use the /dev/random that is on our SSD drive rather than the HDD. How can we have the ...
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Why does `cat /dev/urandom` break your terminal?

In reference to this question: http://serverfault.com/questions/534449 How does cat /dev/urandom make some terminal emulators go wonky?
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Why is “/dev/rdisk” about 20 times faster than “/dev/disk” in Mac OS X

According to the rasbery pi documentation, You can load your OS to a flash card with either /dev/disk or /dev/rdisk. rdisk stands for raw disk. /dev/disk is a block level device, why would rdisk ...
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119 views

What is /dev/blog?

I have tried searching for /dev/blog on google, duckduckgo, etc.; but I cannot find any information about it. I've also asked another sysadmin where I work, but he didn't know what it is used for ...
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460 views

Can't find /dev/root

I am having hardware issues with my main laptop, so until I get it fixed I am trying to use its hard drive on my old laptop. I am using a SATA-USB converter to boot on it. The problem is when I try to,...
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312 views

Ubuntu Drive Mount Order

I have two drives, a 120GB SSD and a 2TB HD. I set the BIOS to boot from the SSD, and an the Drives window of Ubuntu it tells me the SSD is SDB and the HD is SDA. I would expect the SSD to be SDA ...
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Is there a device file in the /dev directory that represents the wireless adapter?

I've been exploring the /dev directory and am curious are all the devices mapped to those files there? Specifically I'm looking for a wireless file. I was hoping to find something like /dev/wifi or /...
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882 views

USB pen drive not getting assigned anything in /dev/

dmesg | tail -f: [17597.228060] usb 1-1.3: new high-speed USB device number 11 using dwc_otg [17597.330548] usb 1-1.3: New USB device found, idVendor=18a5, idProduct=0300 [17597.330580] usb 1-1.3: ...
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100 views

Should a dev team use a local database or a remote shared one? [closed]

I'm part of a team of developer and today, we do our developments against an Oracle 11g database installed on our own machine each. I would like to know your point of view about this way of working ...
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45 views

what's the easiest way to match up /dev/sdx with a device mounted in /media?

I can never remember which device is what so when it comes to partitioning, etc. I'm afraid of messing up the wrong drive. Automounted devices like external drives don't seem to turn up in fstab. So ...
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765 views

Mount TMPFS instead of ro /dev

I am working on a ARM-Based embedded system with a custom Debian Linux based on kernel 2.6.31. In the final system, the Root file system is stored as squashfs on flash. Now, the folder /dev is created ...
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785 views

What's '2>&1' and '/dev/null'

I have been browsing through scripts and see 2>&1 & /dev/null everywhere. What are they? After googling, is it different for OS X than for Linux?
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3k views

What is sda1 used for?

I have two partitions: C: and D: (shown in Windows). Then I installed Ubuntu and found out that /dev/sda represents a SCSI disk and a number after sda represents a partition. Now, I assumed I have 2 ...
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Ubuntu installation will not boot, throws error missing file: /dev/sdc1

I tried to install Ubuntu 12.04 and received the continuous message loop: udev[number]: timeout: killing '/sbin/blkid -o udev -p /dev/sdc' [number] I suspect this error happens due to a missing /...
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444 views

sound detection accessing device node directly

I am attempting to invoke a bash action triggered by audio input. A very simple sound detection sensor (no record) with adjustable threshold utilizing a pc's onboard audio chipset and audio microphone ...
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2k views

restore /dev after `rm`ing it

during a gentoo install from the livedvd, there's one step to create a dev dir to be used later in the chroot of the target for the instalation it's done like that mount --rbind /dev /mnt/gentoo/dev ...
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Use /dev/shm sometimes crashes applications

Sometimes I use /dev/shm for temporary files, as big as 500MB, (I have 8 GB RAM - Ubuntu 11.04 x86-64) and when I load StarCraft II (with wine) I might get memory errors in the game (corrupted data or ...
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401 views

Why is the ownership for /dev/input/eventX set to “root”?

Why are /dev/input/eventX permissions/ownership set to crw-r----- root.root? Then no unprivileged user application can program the mouse. According to what I've read it's due to security reasons, and ...
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/dev/sda1, /tmp,/dev/shm

I'm actually putting some files into temporary folder /tmp. And I want to know the capacity of /tmp. I do the 'df -h': Filesystem Size Used Avail Use% Mounted on /dev/sda1 ...
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How can I know what device the file in /dev is mapped to

I have installed a new device in linux. If I enter lspci, i can see the information of this device. But, I do not know which file in dev is mapped to this device.
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Linux: Find out /dev description for a device

I have a microphone that I connected via USB. When I do dmesg it shows [37830.040274] usb 5-1: new full speed USB device using uhci_hcd and address 4 How do I find out what /dev/??? identifier has ...
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2answers
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Adding devices elsewhere on a network to /dev

I was wondering if it were possible to add devices to my computers /dev folder over a network. In linux philosophy, everything is treated as a file, and if I can have my /home/user1 and /home/user2 ...
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97 views

Control device labels in /dev

I have an HP xw8200 workstation running linux with two small, fast SCSI drives hooked up to the onboard LSI SCSI controller. The drives get labeled /dev/sda & /dev/sdb in /dev, respectively. I ...
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What is /dev/mem?

Presumably it's somehow related to memory? What would sudo cat /dev/urandom > /dev/mem do? Trash all RAM? All non-kernel virtual memory? None of the above?