These questions are about Linux in general -- NOT specific to a particular distribution. If the question just happens to be in a Linux environment, please specify your Linux distribution in the body of your question, but do NOT use the /linux tag.

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0
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0answers
250 views

Linux server crash (kernel NULL pointer dereference + soft lockup - CPU#1 stuck)

I have a Linux 3.2.0-4-amd64 #1 SMP Debian 3.2.46-1 x86_64 GNU/Linux server that keeps crashing, usually once every 24-72 hours. I'm running lighttpd, mysql, haproxy and a couple of always-running ...
4
votes
3answers
1k views

timeout without killing process in bash

I have a main script that I'm running, and from it I have a second "slow process" I want to kick off, and "do something" in the main script if it doesn't complete in the time limit -- depending on if ...
3
votes
2answers
1k views

Why CONFIG_NO_HZ is not set by default

In the Linux Kernel CONFIG_NO_HZ is not set. But an initial reading suggests that setting that option would be nice from a performance point of view. But reading some posts like this made me think ...
1
vote
3answers
2k views

How can I start a process using cpulimit?

I am trying to use cpulimit for testing an app I'm developing under low resource conditions, and I need the process to start under the influence of cpulimit. It is not sufficient to start the program ...
1
vote
1answer
336 views

useradd --no-log-init [comprehension question]

TLDR: How is useradd --no-log-init actually used [in GNU/Linux [Debian]? I read the command's man and info page about this option as: »user will not be listed in the lastlog and faillog files &...
2
votes
2answers
2k views

how to add line in a /etc/sudoers file with the help of shell script (50servers)?

Anyone can help me with shell script, I want to know script which can edit /etc/sudoers file and let me add {{{{{userid ALL=(root) ALL}}}} to 50 server I have on same network?
1
vote
1answer
3k views

scp stuck when trying to copy files from Linux to windows

I use the following scp syntax in order to transfer a lot of files from Linux red-hat 5 to windows machine (under Temp directory). SSH server is already installed on windows machine. I use this line ...
1
vote
1answer
145 views

Why is this copy/paste in vim configuration not working properly?

I have the following in my .vimrc vmap <C-c> y imap <C-p> <esc>P So that I can do my classic sortcut for copy/paste. It works fine on Cygwin but not in my ssh session to ...
0
votes
1answer
128 views

Are there any Linux distros that protect against “self-mutilation”? [closed]

Over the past week I have installed and reinstalled Linux several times (Mint 15 in all but one case; Ubuntu 13.04 is too slow on my laptop), and after a mishap with QT today I completely gave up in ...
-1
votes
1answer
116 views

Is Windows Linux based [closed]

Is Windows Linux based? Because I cannot find a stack exchange site for Windows. If there is not sit for Windows can anybody explain how to request a site.
1
vote
0answers
2k views

how does /etc/init.d/networking restart cause wpa_supplicant to be run using the previous configurations?

Background: I use Debian Lenny and have two WiFi interfaces. I use a generic configurations on /etc/network/interfaces iface wlan0 inet static address 10.0.0.1 network 10.0.0.0 ...
3
votes
1answer
325 views

How do I access a flash drive that has been ejected without physically plugging it out and back in? [duplicate]

When I plug in my flash drive, it gets auto-mounted. If I right click on the drive and select 'eject', then it's unmounted. Now, I want to remount the drive in Terminal. How do I do this? I've ...
0
votes
1answer
645 views

Choppy sound when recording sound from my microphone

I've just installed a fresh copy of Linux Mint 15 and so far everything is working ok, but sound from my mic. While talking on skype or just recording the sound produced is very very choppy. I tried ...
3
votes
1answer
6k views

/proc/meminfo MemTotal =?

What elements of /proc/meminfo sum up to MemTotal? Example of tee /tmp/proc/meminfo < /proc/meminfo MemTotal: 1279296 kB MemFree: 164092 kB Buffers: 62392 kB Cached: ...
12
votes
4answers
64k views

How to create custom commands in Unix/Linux? [closed]

I'm a newbie in Unix/Linux environment. Can anyone guide me to create custom commands in Unix/Linux. Thanks in advance
1
vote
3answers
181 views

Mode to set Directory in Only READ-WRITE mode

Can anyone tell me how to set a directory only in read/write mode as below? -rw-rw-r-- I tried with 640,644 but I am able to achieve...
0
votes
1answer
2k views

LIRC does not start after reboot

If I compile LIRC with this patched lirc followed by install using make install it works fine and launches without any error. However, after a reboot the same command fails with following error : ...
1
vote
0answers
94 views

Unable to use ztemf 190A from Aircel in Linux Mint 13

I have installed Linux Lint 13 Mate 32 bit edition. I am not able to use my zte mf 190a 3g datacard given by Aircel as there is no driver for this. I do not know anything about Linux. Modem is shown ...
1
vote
1answer
1k views

Which book of those two should i read to study networking for Unix/Linux administrator? [closed]

I'm quite a beginner to networking, I want to get the information that i need as a Linux/Unix admin. I have two books in hand right now: TCP/IP Illustrated, Volume 1: The Protocols UNIX and ...
1
vote
0answers
151 views

Disk partition emptied during tar backup

This morning I was doing a routine backup of my development drive, one of 4 primary partitions on my hard-drive. The script I ran was: filename="/home/Backups/Devi_"`eval date +%Y%m%d`".tgz" touch $...
3
votes
1answer
242 views

Binding single key (such as 'F1') to multiple keys (such as 'Ctrl+C') in Gnome

I know how to map a single key to a command using the gconf settings. I also know how to map a single key to another key (F1 -> ctrl) using Xmodmap. My question is how can I map a single key such as ...
0
votes
0answers
13 views

Mapping single key (such as 'F1') to multiple keys (such as 'Ctrl+C') in Gnome [duplicate]

I know how to map a single key to a command using the gconf settings. I also know how to map a single key to another key ('F1' -> 'CTRL') using Xmodmap. My question is how can I map a single key ...
1
vote
1answer
276 views

Efficiency of Linux Kernel [closed]

In a documentary, Linus Torvalds says that even in the future, if anyone wishes to make a new OS from the scratch, they could use the Kernel which he wrote. It was very inspiring. Is it true that ...
2
votes
1answer
144 views

Why do I get one more number of bytes reported in a file?

Why do I get one byte more reported? I do not have a newline at the end. I tested other files with similar result. Using linux 3.2. $ cat testfile.txt aabbcd $ wc -c testfile.txt 7 testfile.txt ...
6
votes
3answers
1k views

Is there a way to select by several conditions in `ps`?

It seems I am missing something blindingly obvious, but still: ps -f -u myuser --ppid 1 Seems to only take a look at parent pid of the process, and returns all the processes that have parent pid of ...
1
vote
0answers
462 views

Any good usb-serial (RS485) adapter to use with GNU/Linux?

I'm having problem with usb-serial (RS485) adapters. Firstly, I tried ch341 without success. The problem in this case is the linux driver, made by reverse engeneering (sadly without any help from the ...
6
votes
2answers
2k views

How to take sha-1, sha-256 or MD5 of CDs / DVDs?

I just tried burning both a Debian CD and a Debian DVD from their .iso files and I've got a weird behavior: the checksum of the CD is correct but the one of the DVD ain't. Here's what working: ...
2
votes
0answers
430 views

After installing VirtualBox to Fedora 17 the system won't boot (NVidia drivers)

My luck I had couple of older kernels, which work. The new kernel, probably somehow patched by VirtualBox fails to load. What fails is X-server, when it tries to start, here's the log: [ 14.284] (...
2
votes
1answer
2k views

Attempting to detect acceptable LDAP base DN defaults for various directory servers in a bash script

Basically, I'm writing a script that determines an acceptable default for a base DN when pointed at a particular hostname. I'm wrapping it around ldapsearch output. I can do Active Directory by ...
0
votes
0answers
117 views

Mint15, 2 GeForce 450 cards cinnamon crashes

Just installed Linux Mint 15 fresh install, got 2 GeForce 450s w/ 3 monitors. Cinnamon crashes. I used the propriety drives so vmware would have hardware acceleration. I end up in fallback mode, any ...
0
votes
1answer
2k views

Unexpected end of file error when executing script

Can somebody help me debug this simple script. Been trying for 2 hrs now but I cant seem to get it to work. #!/bin/bash echo "Search for MMSC or WAP connectivity errors" sftpErrorCount=$(tail -100 ...
1
vote
1answer
248 views

Bundle my scripts to make an installer in Unix?

We've got a PHP script running MongoDB in the background. I want to make it a bundle (Installer) for Unix. I will use it to install the following on any machines: Install Apache, PHP + MongoDB ...
3
votes
2answers
419 views

How to make directory modication date change when files from that dir change?

For example, if a file has been changed in that directory, then directory modification date should be updated. Basically any changes that happen in that directory should trigger a "touch" on the ...
2
votes
2answers
3k views

Can system calls be interrupted?

Please comment on the following sentence: On the standard Linux kernel without the rt patch, interrupts can't interrupt ongoing system calls. The reason why our machine doesn't stop working ...
1
vote
1answer
366 views

Can we create lvm volume group with mapped device?

I can create a lvm volume group with a loop device. But if I use dmsetup to map the loop device into several devices, then I can't create a lvm group with /dev/dm-. Why is it not possible to create ...
11
votes
1answer
23k views

Limits on the number of file descriptors

I'm trying to install 389-ds, And it gives me this warning : WARNING: There are only 1024 file descriptors (hard limit) available, which limit the number of simultaneous connections. I understand ...
1
vote
0answers
724 views

Restore a Linux backup on virtual machine

I have made a backup of my Linux OS in a bacukp.tgz, the OS is Centos 6.4. Now I want to create a new VMWare virtual machine from it. Do I first need to install Centos from CD or ISO, and then ...
3
votes
1answer
1k views

Are time interrupts always followed by a scheduler call?

When a timer interrupt occurred the ISR is called to service the interrupt. Is it okay to assume that every timer interrupt ends with a call to the scheduler on which process should continue running ...
2
votes
0answers
139 views

Which counter generates timer interrupts?

I did a iotop to observe the interrupts on my computer. This is the interrupt shown most often. 0 [PIC-edge time] 247 Ints/s (max: 389) I believe it's the timer interrupt, well since ...
1
vote
1answer
261 views

chkconfig does not display runlevel links correctly

I am using chkconfig to manipulate runlevel links on my Debian System (LSBInitScripts). I have noticed some inconsistencies, for example According to chkconfig, the script umountiscsi.sh is turned ...
6
votes
3answers
13k views

How can I revert a chmod on the etc directory?

I accidentally executed the following command on the etc directory: sudo chmod -R 700 /etc I know that I have done something very wrong. My terminal now prints: I have no name!@ubuntu: /$ How ...
0
votes
1answer
2k views

What does high, low, negative and constant values from pidstat command mean?

I needed information on the following: Can you please tell me the inference for the following in terms of high, low, negative and constant values from pidstat command in Linux. kB_rd/s, kB_wr/s, ...
4
votes
2answers
4k 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 ...
3
votes
2answers
319 views

Silencing all stdout during bootup

I am looking for a completely silent bootup of my Ubuntu Server 13.04 installation (dumped to file rather than stdout). What I want is the screen to be blacked out (eventually replaced with a logo) ...
5
votes
1answer
2k views

Find driver (which is not automatically installed) for a specific hardware

Is there some general way to find out the name of the driver which I have to install on my linux system given only the hardware name? Maybe some centralized webpage or application which gatters all ...
3
votes
2answers
683 views

how does ssh discover hostnames on the network?

We have a server on the company network named serverA, and if I type ssh serverA, it will connect my PC to this server, even though there is no entry for this server in my /etc/hosts, but I used to ...
3
votes
1answer
865 views

difference between useradd -b and useradd -d

Can somebody please explain to me the exact differences between useradd -b and useradd -d in [Debian] Linux? Both seem to work quite similar to me, but then I spot differences that confuse me.
1
vote
1answer
586 views

How to make dual boot live dvd

Can we make a live dvd with a dual boot option between Ubuntu and Linux mint? I have both the iso's. They both are larger than 800mb. If I will burn 2 dvd's, Then a lot of space will be wasted. So I ...
6
votes
2answers
3k views

How to get differences between different distributions of linux

I tried out Red Hat, Ubuntu, Kali Linux. While working on them I searched for the difference between the distributions of Linux. One thing I got was the difference in Package Management, (.rpm and ....
21
votes
3answers
14k views

Limit outgoing bandwidth on an specific interface

I would like to know the easiest way to limit outgoing bandwidth for an interface. I want to cap the outgoing port speed so that file transfers between my servers don't fail during busy hours. What's ...