Questions specifically about Linux, as opposed to Unix-like systems in general, or to questions about a specific distribution or program.

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6
votes
1answer
1k views

force re-negotiation of PCIe speed on Linux

I'm working with PCIe Gen 3 cards and from time to time they seem to fall back to PCIe 1 or 2 speeds (according to lspci and also observed by the throughput). When rebooting/power cycling the machine ...
7
votes
1answer
30k views

reading from serial from linux command line

I have a serial port device that I would like to test using linux command line. I am able to use stty and echo for sending commands to serial port, but when device responds I have no way of reading ...
4
votes
1answer
4k views

Using the Wifi of a notebook via ethernet for another PC

I want to connect a PC to the internet via my notebook, which is connected to a WLAN. The setup should look like the following scheme: PC (eth0) -> Notebook (eth0) -> Notebook(wlan0) -> ...
1
vote
0answers
589 views

I can't find my tape library changer under centos 5 with a quantum scalar i40

i have a quantum scalar i40 connect on a centos 5 machine trough SAS interface. I fight with it since a while because the media changer does not work. I finally understood yesterday that the system ...
2
votes
1answer
1k views

How Do I use autofs to map a USB drive by its ID?

Goal I have a USB drive -- let's say the drive's ID is /dev/disk/by-id/thediskid I would like to mount the drive -- by ID -- to a folder (let's call it /MOUNT_FOLDER) Question What is the best ...
3
votes
2answers
10k views

Display a file's history (list of users that have modified a file)

Is there a command to display a list of users who modified a file providing a file history? I know that possible with svn/git etc.. but we have a config file that is not in SVN and someone modified ...
7
votes
1answer
782 views

How to find out how fc-match matches?

When I run fc-mach Sans, it returns DejaVuSans.ttf: "DejaVu Sans" "Book" but if it is run like fc-match "Sans " or fc-match "Sans 9" it returns unifont.ttf: "unifont" "Medium". I prefer to always use ...
6
votes
4answers
2k views

Is it possible to change password database file(/etc/passwd) in linux?

Is it possible to change password database file(/etc/passwd) to some other file. How does this authentication mechanism work internally ? Does it depend on pam ?
5
votes
1answer
393 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 ...
4
votes
2answers
253 views

Exiting a pipeline if a former command fails

I'm trying to check the number of running and queued PBS jobs by parsing the output of qstat -tn1 from a bash script. So far, this has worked: count () { qstat -tn1 | awk ' BEGIN { R = 0; ...
6
votes
5answers
462 views

What are the recommended ways of defending a remote *nix install from a hamfisted admin?

Once in a while (often a long while), I have a difficulty where I execute a command that completely screws up a Linux machine. Most recently, I accidentally mounted-again the root partition (thinking ...
3
votes
4answers
8k views

IP of localhost

How does a Linux instance determine its IP address? That is, not the 127.0.0.1. Is this stored in file or does ifconfig somehow calculate it at every invocation? I managed to solve it just to show ...
3
votes
0answers
552 views

Using Creative Sound Blaster on Ubuntu Server

I just got a Creative Sound Blaster for playing audio wirelessly. I connected it to a virtual version of Ubuntu desktop and just had to go into the sound settings and switch it to the USB and the ...
3
votes
1answer
588 views

Set GPIO permissions cleanly

Can the default permissions and ownership of /sys/class/gpio/ files be set, e.g. by configuring udev? The point would be to have a real gid for processes that can access GPIO pins on a board. Most ...
0
votes
1answer
379 views

Is there a way to use/recompile libgio-2.0 on machine with libc-2.5?

I have a program (JavaFX 2, namely), and one of its binaries (libglass.so) requires libgio-2.0.so.0. The problem is, the system, on which I need to run the app, is quite old and mostly out of my ...
2
votes
1answer
912 views

High memory (user space) and highmem (kernel space)

Each process has 2 memory area: User space (high memory) and kernel space (low memmory). In the kernel space, are the first 896 MB used for mapping kernel code (not fully 1 GB)? This means, when a ...
3
votes
4answers
1k views

Clock skews on remote machines

I am performing some experiments on a network of about 10 remote Linux computers which are geographically scattered. I suspect some of them have clock skews but they are seen transiently (eg. once in ...
4
votes
3answers
907 views

Is it possible to download extremely large files intelligently or in parts via SSH from Linux to Windows?

I have a ~35 GB file on a remote Linux Ubuntu server. Locally, I am running Windows XP, so I am connecting to the remote Linux server using SSH (specifically, I am using a Windows program called SSH ...
0
votes
2answers
2k views

How to assign user root rights?

I have Suse Linux on my desktop. So I am root and "normal" user. Frequently e.g. to start tomcat or install/remove a program I should use sudo or switch to super user. But I have defined many aliases ...
-2
votes
2answers
788 views

Entry point of linux kernel [closed]

In the linux kernel is there a file that I can start to add my code, ex. load libraries? thanks
3
votes
1answer
635 views

Routing through iptables

I have this vpn client that touches the routing table and then keeps watching it to exit if it gets touched. It is the kind of setup needed for an endpoint, such as a laptop. I want to use a small ...
1
vote
0answers
277 views

Is openwrt difficult to use for a novice? [closed]

Background I am very interested in openwrt, I like that it's open source and gives you complete, granular control over your router. I'm going to use my router for a home network (with a nas, htpc ...
4
votes
1answer
385 views

Linux support on 2012 MacBooks

I want to buy a 2012 MacBook with the Retina Display. Does it work well with Linux?
2
votes
1answer
3k views

Can I make SSMTP to automatically set the “To:” header?

I'm using the ssmtp package to send e-mail via g-mail. Everything is working fine with it - the only strange thing is that if I send mail via the command line, the "to field" is funky. ssmtp ...
1
vote
2answers
89 views

Linux VPS Configuration

I just recently got my hands on a linux (Fedora) VPS and I would like to ask if there are special configurations that I have to be wary of. Do I still configure it like I would configure a normal ...
3
votes
1answer
2k views

What is the concept of Refresh in Linux, if there is so

I have read in forums and googled results , that Refresh is not needed in Linux (Ubuntu /Linux Mint , etc ) like systems. I never found the reasons or concept behind REFRESHING in Linux. What ...
1
vote
1answer
171 views

IPv6 in IPv4 over LAN

I want to setup IPv6 in my LAN, but also want to have some machine to use IPv4 only. How do I do such setup so that every machine can communicate with each other ? All machines supports dual-ip ...
0
votes
2answers
204 views

Critical Memory [duplicate]

Possible Duplicate: free: output format My Redhat server shows the following: free -m ============= total used free shared buffers cached Mem: ...
1
vote
0answers
23 views

Running Gst Player through command line [duplicate]

Possible Duplicate: Commandline gstreamer player I want to run my Gst Player through command prompt in ubuntu 10.10 please help
1
vote
1answer
1k views

How to know whether wget has completed download successfully?

I attempted to download openSUSE 12.1 through wget. It stopped after 64% showing: 05:54:48 (120.30 KB/s) - `openSUSE-12.1-DVD-i586.iso' saved 4429185024/4429185024] It appears that the download is ...
1
vote
1answer
1k views

Alternative to xmllint to check xml validity

Sometimes, I have to check the validity of some big xml files against a xsd file. The biggest xml file I received had a size close to 1.5GB. xmllint took all my RAM and almost all the swap space, for ...
2
votes
1answer
570 views

Bumblebee (Optimus) Service Won't Start w/ 3.4 Kernel on Fedora 16

I'm using an ASUS laptop (MUXless graphics) w/ a GT 630M (re-branded 540M) GPU and only Fedora 16 installed. I installed bumblebee and the NVIDIAdrivers using the instructions described here: ...
5
votes
5answers
3k views

How can I mount partitons in a full disk image (i.e. image with partition table) with fuse?

It's a bit indirect, but it's possible mount a partition with a disk image using mount or losetup's "offset" parameter. I'm looking to be able to use fuse to do the same thing in user space Use ...
1
vote
3answers
1k views

Disabling email for an account

I have an amazon ec2 instance running ubuntu. There are only a couple of user accounts and the server is used to host a small web app. Apparently, by default, each user account has an email account. ...
0
votes
3answers
596 views

Zip file using tar on linux server

I'm trying to make a zip file out of some files but when I extract the zip I only get 1 file. tar cfvz test.zip file1.mp3 file2.mp3 file3.jpg And after I extract test.zip I only get a "test" ...
8
votes
2answers
13k views

Effect of entries in /etc/securetty

By default on RHEL 5.5 I have [deuberger@saleen trunk]$ sudo cat /etc/securetty console vc/1 vc/2 vc/3 vc/4 vc/5 vc/6 vc/7 vc/8 vc/9 vc/10 vc/11 tty1 tty2 tty3 tty4 tty5 tty6 tty7 tty8 tty9 tty10 ...
6
votes
1answer
2k views

Can Yum express a preference for x86_64 over i386 packages?

I run a 64-bit version of CentOS5. At the moment, when I run Yum updates or installs, unless Yum is purged of i386 packages prior, it will install i386 packages when x86_64 are available. Is it ...
4
votes
5answers
410 views

How does this directory use so much space

Unix is not my native language and I'm getting confused by their concept of filesystems. When I look at my free space I see: /$ df -kh Filesystem Size Used Avail Use% Mounted on ...
20
votes
2answers
19k views

Linux: How to find the device driver used for a device?

If my target has one device connected and many drivers for that device loaded, how can I understand what device is using which driver?
5
votes
3answers
825 views

Advantage to using Linux over Windows? [closed]

I want to get into using Linux more, all my programming and development has all been done under Windows. But I am wondering what is the core advantages to using Linux over Windows? What can I do in ...
7
votes
6answers
24k views

exit out of all SSH connections in one command and close PuTTY

Is there a way to back out of all SSH connections and close PuTTY in "one shot"? I work in Windows 7 and use PuTTY to SSH to various Linux hosts. An example of the way I find myself working: SSH to ...
1
vote
1answer
2k views

Bridging ethernet interface

I have a server with 4 public IP's. I have it with this configuration and I want to bridge the interface eth0 for using it with KVM: So, I have 3 IP's (A.B.C.144, A.B.C.145, A.B.C.146) and another ...
2
votes
0answers
45 views

Disable the GIO network extension?

I don't use any LAN, so the following "Network" is useless to me: I checked the source code partially and it seems to be using the GIO network extension. How can I disable this without modification ...
1
vote
2answers
255 views

File encryption and decryption on Linux using ucrypt

A few years back, I was using the ucrypt utility on CentOS 5. Now I am using Fedora 11 and need ucrypt for file encryption and decryption, but I don't have a backup of the old system. Where can I find ...
5
votes
4answers
7k views

Switch Fn key state

I have this issue with Lenovo Thinkcentre Edge. Its keyboard has Fn key, which acts in my Ubuntu (with Fluxbox) as if it is always "active/pressed". I can't use standard F1-F12 keys unless I hold ...
8
votes
2answers
1k views

CPU stuck at 99% for a few hours. Really need help figuring out logs

extract from syslog: CRON[pid]: (user) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -depth -mindepth 1 -maxdepth 1 -type f -cmin ...
3
votes
4answers
11k views

How to start changing linux source code to make custom OS?

I am doing Under Graduation in CS Major, have medium level knowledge in C, C++, and Java and also learned some operating system concepts (as they are in my course syllabus). I have heard that we can ...
1
vote
0answers
423 views

error: implicit declaration of function ‘rt_dev_socket’

The developer says: http://comments.gmane.org/gmane.linux.real-time.rtnet.user/2546 Now how can I tell the Makefile to look for headers in /usr/local/rtnet/include respectively ...
6
votes
1answer
11k views

Changing screen resolution/geometry of a vncserver without randr in Linux

I want to change the resolution / geometry of my VNC session dynamically without affecting the programs running inside it. I referred: Changing the resolution of a VNC session in linux. I don't have ...
3
votes
1answer
506 views

Rationale for making user space text segment start at 0x8048000

I read somewhere that (at least since Linux v. 2.6) all user-space code is placed at load address 0x8048000 in the virtual memory address space. My own observations confirm this. I have done a cat ...