Tagged Questions
3
votes
3answers
58 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 ...
1
vote
2answers
46 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
69 views
Explain EV in /proc/bus/input/devices data
Can anybody explain to me what the EV value in /proc/bus/input/devices is?
The keyboard always has value 120013. Why?
3
votes
2answers
53 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?
4
votes
2answers
47 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
2answers
221 views
How does cat know the baud rate of the serial port?
I regularly use cat to view debugging information in the console from my FPGA development board over the serial connection, but I never have had to tell linux what the baud rate is. How does cat know ...
3
votes
2answers
96 views
How to grant non-root user access to device files
I have device file that appears in /dev when a specific board is plugged in. The read and write operations to it work just fine, but in order to open the device file the program needs to be executed ...
2
votes
1answer
64 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 ...
2
votes
0answers
83 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 ...
2
votes
1answer
47 views
Standard way to expose device file to userland applications running on an unprivileged user account?
I just finished the first version of a Linux kernel module I've written in C. The module creates a device file (/dev/wn0) that controls a USB device with three LED lights. For example, running as ...
5
votes
4answers
252 views
Testing, from a script, if audio devices are in silent?
Is there a default program where I can check if my audio devices are in silent?
Edit: By silence, I mean that if there is something playing on that (not just activated or opened)
Something like ...
2
votes
2answers
289 views
Why are there so many virtual terminal devices?
I've been reading the advanced linux programming book availalble free online linky and it mentiones about virtual terminals which if I understood it correctly it is a Linux specific feature (not in ...
2
votes
0answers
163 views
How do I let an SDL app (not running as root) use the console
I want to use an SDL-based program to display graphics on the console, without having to log on from the console, and without running the program as root. For example, I want to be able to run it via ...
3
votes
1answer
1k views
/dev/sdb: No such file or directory (but /dev/sdb1 etc. exist)
I'm not sure what is wrong here but when running fdisk -l I don't get an output, and when running
fdisk /dev/sdb # I get this
fdisk: unable to open /dev/sdb: No such file or directory
I'm ...
3
votes
2answers
756 views
What causes /dev/disk/by-label to be populated?
I've noticed that Linux distributions typically have a /dev/disk/by-label directory, but this isn't always the case (For example, the CirrOS Linux test image doesn't have one).
What's required on a ...
1
vote
0answers
146 views
Is it possible to use a PS3 controller to emulate an xbox controller?
I have my PS3 controller connected through USB and while that works fine, no applications seem to support its keymap. So my question is whether it's possible to make it emulate an xbox controller ...
2
votes
2answers
600 views
Prevent usbhid from claiming USB device
Directly related: Prevent claiming of novelty usb device by usbhid so I can control it with libusb?
I want to access an RFID reader (works as HID device) from a program that uses libusb-0.1. In the ...
3
votes
1answer
209 views
How do I setup more then 10 loopback device?
From this answer the solution is to
modprobe loop max_loop=64
Which makes me allowed to use 64 loopback devices then
mknod -m 660 /dev/loop8 b 7 8
To create the devices. I did this for 8, 9, 10 ...
3
votes
0answers
406 views
How do I find out the device node corresponding to my device in SuSE 8?
I'm forced to work with a bunch of point-of-sale systems running SuSE 8. They are my client's computers. We are stuck dealing with these old systems until they get to upgrade their whole fleet to SLE ...
2
votes
1answer
94 views
Why slowusb and scandelay?
I'm running linux-3.4.9 compiled with genkernel, and booting from a USB HDD. I was slightly annoyed by the slow boot process, in particular, during the execution of genkernel scripts at the modprobe ...
2
votes
3answers
308 views
Chroot Risks w/ /dev and /proc
I am planning to set up a few chroot jails for some users to run/test Java applications (lets just assume each application is untrusted). Is there any risk involved with mounting /dev and /proc into ...
2
votes
1answer
3k views
GSM modem does not create /dev/ttyUSB file
I installed Kannel in a server, and I want to use a GSM 3G USB modem to
send/receive SMS messages, as described in section SMS Centers > GSM
Modem of the Kannel User Guide.
I have already installed, ...
9
votes
1answer
444 views
What happens when I do “cat debian.iso > /dev/sdX”?
I'm creating a live-USB and don't understand precisely: what happens when I copy a file (or even a file system) directly to a device node (as opposed to a file system)?
0
votes
1answer
92 views
Using USB hub for keyboard and mouse in multiseat
I want to configure a 2 user multiseat in Linux.
Is it possible to configure keyboard and mouse for second seat with a USB hub on a single USB port or I need to connect each of them to a separate USB ...
5
votes
1answer
107 views
Does the suid bit have any meaning for device files?
Does the suid bit have any special meaning for device files in Linux ?
2
votes
0answers
149 views
How to know the event by looking at /dev/input/by-id
I want to access the keyboard device driver. I usually accesses it by looking at
/dev/input/by-name but the event provided by it gets changed every time I log in.
After searchin on the Net, I found ...
5
votes
1answer
212 views
What driver is behind a certain device file?
Given a device file, say /dev/sdb, is it possible to determine what driver is behind it?
Specifically, I want to determine what driver my storage devices are using. fdisk -l lists 2 devices: /dev/sda ...
0
votes
1answer
226 views
Do I need ephemeral storage?
I was running a small instance on Amazon EC2. I'm trying to migrate it to a micro as it requires very minimal processing power. One thing I just learned though, is that micro instances do not come ...
1
vote
0answers
66 views
“nopage” method for ISA vs PCI [closed]
This is with reference to LDD3 ch. 15, section "Mapping memory with nopage". I am having trouble understanding the third paragraph on page 429. It says:
Note that this implementation works for ISA ...
2
votes
0answers
48 views
What are the differences between the current Linux kernel and the Unix SVR4 kernel in terms of device drivers+i/o and virtual files systems?
Yes I realize that Linux supports many more file systems and recognizes more devices than Unix SVR4. I'm interested in what the differences are in the abstraction on top of an actual file system, or ...
5
votes
1answer
230 views
Does the kernel delete entries in /dev on an initramfs?
I have a fully custom, minimal, embedded Linux (vanilla, 3.3.8, i486, Vortex86dx) system that boots from an initramfs image. No standard distribution scripts are used, just a single rcS file that does ...
1
vote
1answer
322 views
Can I use a parallel port as a CUPS input device?
I have an old piece of a hardware that does diagnostics on medical equipment. It prints out results over a parallel port. Is there any way to have CUPS accept jobs from a parallel port and redirect ...
3
votes
1answer
1k views
How can I uniquely identify which device is on USB `hub 6-0:1.0: port 2`?
How can I uniquely identify which device is on USB hub 6-0:1.0: port 2?
I receive messages in my dmesg every now and then and I want the system to tell me which device is connected to that port.
...
1
vote
0answers
381 views
Build an Affordable Linux Tablet [closed]
I have 3 young children and my wife has asked that the girls get a tablet, for basic gaming, and online web tutorials (school work usually).
Has anyone created or built a good affordable Linux ...
3
votes
4answers
1k views
GNU/Linux (Debian): detecting hard-disks mappings?
Let's suppose you have two hard-disks:
one internal (boots GNU/Linux);
one external (USB).
"fdisk -l" detects both, but will not tell you which is /dev/sda and which is /dev/sdb. "lsusb" will tell ...
3
votes
2answers
286 views
Choosing a device name under /dev from the kernel command line
I am booting CentOS via a USB install. The boot method is simply booting the ISO from GRUB2 installed on the USB Key.
The USB key always gets the "name" /dev/sda. Can I change that name from the ...
6
votes
2answers
3k views
How do mouse events work in linux?
This is mostly out of curiosity, I'm trying to understand how event handling works
on a low level, so please don't reference me to a software that'll do it for me.
If for example I want to write a ...
4
votes
3answers
1k views
What do first column in /proc/mounts really mean in Linux?
Run cat /proc/mounts and I get this (simplified):
rootfs / rootfs rw 0 0
proc /proc proc rw,relatime 0 0
/dev/sda1 / ext3 rw,relatime,errors=continue,barrier=1,data=ordered 0 0
io /etc/blkio cgroup ...
5
votes
3answers
1k views
Understanding /dev and its subdirs and files
$ ls -l /dev/stdin /dev/fd/0
lrwx------ 1 tim tim 64 2011-08-07 09:53 /dev/fd/0 -> /dev/pts/2
lrwxrwxrwx 1 root root 15 2011-08-06 08:14 /dev/stdin -> /proc/self/fd/0
$ ls -l /dev/pts/2 ...
6
votes
3answers
3k 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 ...
1
vote
4answers
2k views
cfgmgr like command under Linux?
cfgmgr is a command under AIX/ksh that checks for new hardware; e.g. new HDD's that have been added without a shutdown.
Question: Are there any similar commands under Linux? If "fdisk -l" doesn't ...
5
votes
1answer
597 views
How to be notified when a USB device was plugged?
My system have to auto-mount for usb devices, how can I be notified when a usb device is plugged? Where can I read more about?
I would like to treat that using shell script or C.
9
votes
3answers
2k views
Shell command to read device registers?
On a single-board computer running Linux, is there a way to read the contents of the device configuration registers that control hardware? I think it would be a wrapper for inw(), more or less.
I'm ...
23
votes
7answers
44k views
How do I find out what hard disks are in the system?
I need to know what hard disks are available, including ones that aren't mounted and possibly aren't formatted. I can't find them in dmesg or /var/log/messages (too much to scroll through). I'm hoping ...
3
votes
1answer
2k 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 ...
