devices refers to questions about the Unix/Linux device special files, normally these are under /dev. Do not use this tag for physical devices (for that use e.g. usb or pci).

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3
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0answers
165 views

How to rename devices for graphical output such as VGA0

On my Laptop the names of my graphical outputs change depending on what chip is activated in the BIOS. This leads to problems in some scripts where outputs such as VGA-0 or LVDS-0 are specified. So I ...
4
votes
2answers
2k views

Can I stop Linux from listening to a USB input device as a keyboard, but still capture events with a program?

I have a USB barcode scanner at /dev/input/event0 (/dev/input/by-id/usb-Metrologic_Metrologic_Scanner-event-kbd), and scanning a barcode causes it to send keypress events. I'm capturing these ...
0
votes
2answers
158 views

ECC on a single block device

I have an SSD that I suspect failing silently now and then. I have run badblocks on it and it is clear that it is not bad sectors but might instead be some race condition in the electronics, in which ...
0
votes
1answer
89 views

Random bug in Linux

Some time ago, I remember reading an article on randomization in computing, and how random you can actually get a system to be. The article came about, if I'm not mistaken, because of some seemingly ...
0
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2answers
341 views

IO utilization for /dev/null redirection?

I always use nohup to start my system. However, the output to nohup is so big that I'm thinking to redirect it to /dev/null. My concern is, will redirecting to /dev/null also incur some I/O operations ...
2
votes
1answer
210 views

GPS Device Attached to Linux Mint 15

I purchased a Silvercrest GPS device from Lidl recently, but the software that came with it is a tad "underpowered" to say the very least and has no Linux support. I'm attempting to get at the raw ...
1
vote
1answer
1k views

“Permission denied” when writing to /dev/stdout

Why cannot I write to /dev/stdout? I am logged in as the root user, what greater permission could I have? root@ubuntu:/# tcpdump -i 2 -w /dev/stdout tcpdump: /dev/stdout: Permission denied The ...
2
votes
1answer
1k views

ffmpeg webcam to device driver , output 8 bit grayscale

With the following command i'm trying to capture 10fps and send them the device driver. Now i want 8 bit gray raw frames (640x480= 307200 bytes per frame) to be send to the device driver. I can't ...
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 ...
11
votes
4answers
10k views

Find out what device /dev/root represents in Linux?

On linux, there is a /dev/root device node. This will be the same block device as another device node, like /dev/sdaX. How can I resolve /dev/root to the 'real' device node in this situation, so ...
3
votes
2answers
3k views

What is a device controller, and where does it fit in between the kernel and the device?

Can someone please explain the concept of a device controller (hard disc controller, NEC PD765 compatible controller etc.). Here are some definition of key terms which might be needed for the ...
1
vote
1answer
452 views

dd outputting: “function not implemented” when trying to write to /dev/sg11

I'm trying to use the following command: dd if=/dev/urandom of=/dev/sg11 bs=16K count=1 But when executing it, I get the following error: dd: writing `/dev/sg11': Function not implemented When I ...
6
votes
2answers
2k views

Why are there so many virtual terminal devices?

I've been reading the Advanced Linux Programming book and it mentions about virtual terminals which, if I understood it correctly, it is a Linux-specific feature (not in Unix) to allow multiple login ...
1
vote
1answer
84 views

Need list of HDD devices excluding my os HDD

I want list out whole HDD device excluding my os running device attached to my system. I did lot's of googling and fired many more commands in command line of linux. but can't gating proper output. ...
3
votes
1answer
502 views

How to get the actual keyboard device given the output of /proc/bus/input/devices?

When I run: cat /proc/bus/input/devices ...I receive the following output: ... I: Bus=0003 Vendor=040b Product=2000 Version=0110 N: Name="Generic USB Keyboard" P: Phys=usb-0000:00:1d.0-1/input0 ...
1
vote
2answers
744 views

Meaning of “target” in virsh XML VM definitions.

I recently found that the target=hda tag in virsh was actually not translating into guest OS (guest OS's use /dev/sdX as the disk device names, in general, it seems). virt-install and /dev/hda vs. ...
1
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2answers
1k views

virt-install and /dev/hda vs. /dev/sda

It appears that my virt-install xml file (i.e. created when defining a VM) specifies targets "hda", "hdb", and so on as the devices for disks, however, the VM, once created, lists /dev/sda, /dev/sdb, ...
3
votes
1answer
597 views

Why are devd rules applied before devfs rules?

My problem I have the following lines in /etc/devd.conf which execute the usbhidaction for a /dev/uhid* device with the named vendor and product id. attach 100 { match "vendor" "0x046a"; ...
6
votes
1answer
1k views

Find out if a specific device is an USB mass storage

Context I'm automating SD card imaging from an existing dd factory image. The SD card is always connected through an external USB card reader and thus appears in the system as a SCSI block device ...
0
votes
2answers
805 views

Cheap 100% Debian compatible ultrabooks [closed]

I'm looking for relatively cheap ultrabooks with 100% Debian compatible features. I have several ultrabooks on my list but they contain some additional features which i don't need (additional ...
2
votes
1answer
2k 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 ...
1
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0answers
661 views

Check if Keyboard and Mouse are plugged in

Is there a way to detect if a keyboard and a mouse is plugged in (and working) in Linux? This will be embedded in a PXE setup, so I only have Kernel + Modules and Busybox available. Bonus question: ...
5
votes
2answers
463 views

Can I query which processes (if any) are currently accessing the microphone?

I'm running Debian (technically Raspbian), trying to get a Star-Trek style voice-command system. I've got it mostly up and running, but in the interests of privacy and all that jazz, I don't want my ...
2
votes
1answer
99 views

Assigning static device path

I have 4 flash cards plugged in, sequentially named by system: /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 I want to assign static pathes to them, so every time the system boots up their pathes will ...
1
vote
2answers
214 views

/dev/console points to tty0?

I've been trying to understand the /dev/console device, but there are a few things I'm not clear on: What is the purpose of this device? From what I can gather it's just a place for the kernel to ...
2
votes
1answer
518 views

open() console for default file descriptors

I'm reading a shell program implementation in C ( the xv6 shell from MIT's 6.828 Operating System Engineering course ). The main() function for this shell starts with the following code: //Assumes ...
-1
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1answer
360 views

what type of device drivers are available in linux [closed]

The different types of device drivers used in linux are character device and block device. Is there another classification?
2
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2answers
262 views

Detecting the device of a crypto mount

I have an external eSATA-hdd on an OpenSUSE 12.2 system. The external hdd has an LVM on a dm-crypt partition. I mount it by powering it up and then doing rescan-scsi-bus.sh cryptsetup -v luksOpen ...
10
votes
1answer
10k views

using devtmpfs for /dev

I have noticed the following option in the kernel: CONFIG_DEVTMPFS Device Drivers -> Generic Driver Options -> Maintain devtmpfs to mount at /dev And I see that it is enabled by default in ...
1
vote
1answer
3k views

pvcreate error on partition

I can't create this partition, I'm getting this error shown below: Device /dev/mapper/vg_paperino-lv_rootp1 not found (or ignored by filtering) Below are the steps that I'm doing on CentOS: ...
1
vote
1answer
594 views

Creating a terminal device for interprocess communication

I'd like to know how to create a terminal device to simulate a piece of hardware connected through a serial port. Basically, tty device with a certain baud rate that can be read from and written to ...
1
vote
1answer
708 views

Installing a platform driver

I have recently acquired a device driver for an integrated watchdog timer on a x86 board on which I am running a minimal Linux system. The kernel is 3.6.11 and it has been built using buildroot. My ...
3
votes
2answers
453 views

Why doesn't `head -c 2 /dev/hwrng` work?

I have an Atmel 97SC3201 in my computer and set the following in the kernel: CONFIG_HW_RANDOM_TPM CONFIG_TCG_TPM CONFIG_TCG_ATMEL /dev has tpm0 and hwrng, but running this command returns the ...
5
votes
3answers
9k views

RHEL: Creating stable names for network interfaces

We have a RHEL 5.5 box with 8 interfaces. And the eth interface naming is flip flopping. Sometimes eth0 comes up on physical port 7th, and sometimes on another physical port. We want the naming to ...
3
votes
2answers
349 views

Automated partition selection in bash script

I'm trying to write a bash script to run from Linux on a CD or flashdrive that can mount Windows and change stuff, but I don't know how to go about detecting which partition/drive is Windows. My best ...
5
votes
2answers
4k views

Linux : Major and Minor device numbers

What types of devices fall under the major device number category and what types of devices fall under the minor device number category. What is the real difference between the two categories?
7
votes
2answers
6k views

wlan number assignment

How or where does Linux determine the assignment of a network device? Specifically, wlan0 or wlan1 for wireless USB devices. I plugged in a TP USB wireless a while ago, and it was assigned wlan0. I ...
5
votes
1answer
4k views

Why do my SATA devices show up under /proc/scsi/scsi?

I have 3 SATA devices on my system. They show up under /proc/scsi/scsi, although these are not SCSI devices. Why do my SATA devices show up under the SCSI directory? $ cat /proc/scsi/scsi Attached ...
10
votes
2answers
9k views

set baud speed for tty

How do I set the baud speed for a specific tty (in this case a serial port)? I tried using stty -F /dev/tty.iap ispeed 19200 But get the error Invalid argument for every speed I try (2400, 4800, ...
2
votes
0answers
176 views

Block Devices & Partitions

I partitioned a microSD card (mmcblk1) into two partitions mmcblk1p1 and mmcblk1p2. If use a dedicated card reader I am able to see the entire SD card and its partitions using various disk management ...
0
votes
0answers
21 views

How to associate device to sata port disk [duplicate]

I have 2 hard disks connected to 2 sata ports. The disks are associated to /dev/sda and /dev/sdb. These hard disks are in software raid so it happens that the system can go for some time with only ...
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vote
4answers
6k views

Updated Fedora 18 - no sound devices, just dummy output

So, yesterday I updated the recently released Fedora 18, this has been done: Packages Altered: Updated grubby-8.20-1.fc18.x86_64 @?fedora Update 8.22-1.fc18.x86_64 ...
0
votes
2answers
90 views

Changes to files don't show up until the partition is unmounted

I have a FAT32 filesystem mounted. After changing a file on it, I can read the file back and still see the old version. My changes don't actually persist until I unmount and remount the partition. Is ...
2
votes
1answer
146 views

What is the source of truth for currently active tty/pts connections?

I'm looking for a simple way to determine the number of currently logged in users, using only the filesystem and basic bash functions (instead of using binaries). The uptime binary appears to be ...
0
votes
1answer
810 views

remove /dev/mapper/fedora-root and /dev/mapper/fedora-swap

I want to replace Fedora 18 with Ubuntu but I have these devices listed when partitioning. I only have a hard disk labelled sda, where does these virtual device come from? How I do remove them?
33
votes
4answers
27k views

What is the mknod command used for?

I just started using Ubuntu as my main OS and I wanted to learn about things I should not do, and learn by the bad things people have done in the past. I came across these email about horror stories ...
5
votes
1answer
3k views

Query USB current

How can I obtain information about the amount of current negotiated by a device attached to a USB port? I am looking for information similar to this presented by OS X in terms of current available ...
0
votes
2answers
436 views

Problem mounting my iRiver story HD on Ubuntu

I would like to connect my iRiver Story HD to my ubuntu 12.04 machine but as I connect it I get this error: Unable to mount Story HD Error mounting: mount: wrong fs type, bad option, bad ...
16
votes
2answers
3k views

bash script to detect and record mouse movements?

I need to be able to record the mouse movements every so often (every .2 of a second for example) and have them in a coordinate representation instead of a diff. I found the following script: ...
3
votes
0answers
240 views

How to route one video device to multiple programs

I'd like to direct the output of a single capture card (Hauppauge PVR-150) to two programs: VLC (for streaming on LAN) and MythTV for scheduled recording. I think it's possible to do this with the ...