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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5
votes
2answers
64 views

What are pending signals?

When looking at the limits of a running process, I see Max pending signals 15725 What is this? How can I determine a sensible value for a busy service? Generally, I can't seem to find a ...
1
vote
0answers
14 views

Using a rados block device as block device in libvirt qemu

What is the difference between using a rados block device in libvirt qemu with disk type='network' and disk type='block'? The ceph guide tells me to do the following: <disk type='network' ...
1
vote
0answers
18 views

What is the correct way to start a container with a given command?

I want to create a set of containers for simulating network traffic. Inside each of the containers, I would like to set a different network delay. Right now I am doing it manually using this command, ...
0
votes
0answers
21 views

Where am I supposed to put PyCharm files?

I've just downloaded PyCharm (pro) for Linux (I'm running Ubuntu). It's basically a zipped directory containing everything it needs to run (tree below), including an entry point (bin/pycharm.sh). ...
17
votes
7answers
56k views

Show top five CPU consuming processes with `ps`

How to show top five CPU consuming processes with ps?
0
votes
0answers
20 views

2 X 2TB HD in RAID1 config, “Data volume failed to mount” error

I am using a Western Digital My Book Live Duo and for some reason it decided to go bad on me. The WD support people usual answer is that the device is bad and they even upgraded my warranty to get a ...
0
votes
0answers
17 views

memtest86+ doesn't show up in grub

According to my package manager memtest is installed and both memtest68+.elf and memtest86+.bin are in my boot partition yet grub doesn't give me the option to boot to them. Is there anyway to add the ...
0
votes
0answers
20 views

Centos 7.1.1503 no longer has some static libs that python packages assume are present

I ran repoquery -ql readline-devel and it revealed that only various .so libs are a part of this repository. /usr/include/readline /usr/include/readline/chardefs.h /usr/include/readline/history.h ...
-1
votes
0answers
19 views

network block device: a port was specified but old style export were not requested

I configured the nbd-server in Ubuntu. I configured the following [generic] [myexport] exportname=/dev/sda1 port=9000 Now I restart the nbd-server service #service nbd-server force-reload but ...
0
votes
1answer
26 views

Linux driver privileges

I've loaded a custom driver to linux via mknod. However, now any programs I write to use it need to be run using sudo, which is difficult to do when I'm using an IDE. Is there any way to adjust the ...
25
votes
9answers
2k views

Uninstalling programs on Linux

I've been using Windows and Mac OS for the past 5 years and now I'm considering to use Linux on a daily basis. I've installed Ubuntu on a virtual machine and trying to understand how I can use Linux ...
1
vote
2answers
787 views

Linux guest VM on mac host - Keyboard

I use a Mac as a development box, but am slowly transitioning to Linux. So I am spending the majority of my time in the Linux guest VM while working. But I still spend a fair amount of time in Mac ...
2
votes
3answers
54 views

Bash | port killing loop fails

I am trying to create a bash function which should kill all processes using some ports specified in port_array. The kill-port function works if I call it myself with a port e.g. with kill-port "80";. ...
0
votes
0answers
10 views

How to remove previous version of centos7 and install fresh centos7 in Toshiba Satellite using bootable USB

My centos 7 has been corrupted. I want to install fresh centos7. When I run rpm -q kernel. It gives the following results kernel-3.10.0-123.el7.x86_64 kernel-3.10.0-123.20.1.el7.x86_64 ...
1
vote
1answer
47 views

Is it possible to speed up my Linux Clock?

Is it possible to modify the Unix Time Clock so that the clock is running ten times faster? Something like a fast-forward by increasing a clock frequency or change the clock tick time? Background is ...
6
votes
2answers
12k views

IPTables - Port to another ip & port (from the inside)

I currently have a NAS box running under port 80. To access the NAS from the outside, I mapped the port 8080 to port 80 on the NAS as follow: iptables -t nat -A PREROUTING -p tcp --dport 8080 -j DNAT ...
1
vote
4answers
76 views

How to stop minute cron job?

I have a program written in python; my program scrapes a value from some financial website every minute and pushes that value into my DB. My program takes like 1 or maximum 1.5 seconds to do this ...
5
votes
1answer
2k views

Running bzImage in QEMU: Unable to mount root fs on unknown-block(0.0)

I compiled the kernel by doing make menuconfig and make. I was trying to run the bzImage in qemu, by doing qemu -kernel bzImage but it didn't work out with the error message: Unable to mount root fs ...
-1
votes
0answers
23 views

Do not work shortcuts in Fedora 21

In Fedora 21 some shortcuts don't work. There is a problem with combinations which have more than two keys (ctrl+shift+tab, ctrl+shift+← etc). Another problem with the Win+R or F12 hotkeys to call ...
0
votes
0answers
20 views

Link Speed for wireless connections [migrated]

I am working to implement a benchmarker for wireless connections. How can I determine the link speed in mbps? I am working with C language and Linux system.
0
votes
1answer
41 views

Windows to Linux (rsync and ssh) [closed]

I'm trying to backup the folders in Windows Pictures to a remote Linux directory. This is what I have: rsync -av ssh /cygdrive/c/users/Owner/Pictures/ blah@192.168.1.10:/var/files/ImageSync/ I got ...
1
vote
1answer
45 views

sort file based one colum and group by another column

I have a file of three columns: 1 A 0.5 2 B 0.7 3 A 10 4 C 4 5 B 4 I want to sort the file by increasing order of column 3 and group by column 2 1 A 0.5 3 A 10 ...
0
votes
1answer
28 views

page up and page down alternative for horizontal scrolling in less

In vertical scrolling using less the page up and page down keys are working. Which keys scrolls one page down/up vertically? The less was started with -S option.
0
votes
0answers
28 views

Assign IP to a device using BOOTP protocol?

I have a device that is BOOTP enabled, I want to assign an IP to this device on Linux. there are these tools that works perfectly ...
0
votes
1answer
34 views

How to format old laptop and install CentOS

I have an old laptop with Windows 7. I want to remove everything and install CentOS 7 to turn it into a server. What I know is that I should format the old OS somehow and get iso image of CentOS and ...
1
vote
1answer
23 views

How does PulseAudio start?

PulseAudio is always running on my system, and it always instantly restarts if it crashes or I kill it. However, I never actually start PulseAudio. I have checked /etc/init.d/ and ...
0
votes
1answer
50 views

Cron Job every 55 minutes [duplicate]

I want cron to be run in every 55 mins. I followed the link CronJob every 25 minutes and my crontab command is */5 * * * * [ $(( $(date +%s) / 60 % 55 )) -eq 0 ] && wget ...
3
votes
2answers
705 views

Can you create a volumegroup in LVM that all the Logical volumes created under it will be thin provisioned?

I would like to know if it is possible to create a volumegroup in LVM that all the Logical volumes created under it will be thin provisioned? This will be used on RHEL 6 which does include thin ...
1
vote
0answers
12 views

rpm --verify does not inform about missing file

I noticed there is a missing file in the MySQL installation in a RHEL server. I want to know if there are more missing files so I tried to use rpm --verify (or rpm -V), however it doesn't output ...
5
votes
2answers
709 views

Compiling the kernel with default configurations

Assumptions: The platform: anisha@linux-dopx:~/> uname -a Linux linux-dopx 2.6.34-12-desktop #1 SMP PREEMPT 2010-06-29 02:39:08 +0200 x86_64 x86_64 x86_64 GNU/Linux The kernel downloaded is the ...
-1
votes
1answer
27 views

how to convert video into webm format using ffmpeg in centos

how to convert video into webm format using ffmpeg and libvpx in centos I have install ffmpeg and libvpx in centos.but it's doesn't convert mp4 format into webm format. but in windows i have check, ...
3
votes
2answers
4k views

How to reduce ClamAV memory usage?

I'm running a Ubuntu based web server (Apache, MySQL) on a 512MB VPS. This is more than sufficient for the website it is running (small forum). As I wanted to add some protection against viruses I ...
2
votes
1answer
478 views

LFS 7.5 - Glibc-2.19 compile errors at section 6.9, are they fatal to my LFS build?

I am using a host Ubuntu 14.04 system, and I am currently going through the Linux From Scratch guide here. At section 6.9, http://www.linuxfromscratch.org/lfs/view/stable/chapter06/glibc.html, after ...
3
votes
1answer
45 views

Prevent a lot of brute force attacks on Exim2

Some people or computers have been trying to log in a lot of times on my Linux DirectAdmin server over the last few days. I am receiving a lot of messages of brute force attacks for Exim2 in ...
2
votes
1answer
20 views

/dev/mapper in fdisk

After installing CentOS, I see several lines like /dev/mapper/centos_jackpc--11-swap and /dev/mapper/centos_jackpc--11-root when I issue fdisk -l. What is the purpose of these? And why do they not ...
1
vote
0answers
10 views

Skip syslog/rsyslog logging of certain cron jobs

In most GNU/Linux distributions the default is to log start (and many different events) of every cron job to syslog. It's rather convenient, but not for a very frequent jobs, which started, say, every ...
2
votes
0answers
47 views

How to keep my C program from terminating when CTRL-C is pressed? [migrated]

AFAIK this has something to do with "catch the SIGINT" but I'm looking for more details. Like many others I learn C by writing my own CLI that can start other program located by the environment ...
0
votes
0answers
5 views

videoconferencing/audio-only-conferencing on LAN

The given scenario is an office-building with several floors. Using linux servers and linux clients it is necessary to create a system for videoconferencing or if not possible then audio-only ...
0
votes
1answer
14 views

Dual booting with two drives

So I need to install a microsoft product on one of my drives today sadly. My current setup is so that I have a SSD which has Linux on it. And a 1 TB HDD which just extends my Videos and Documents ...
1
vote
1answer
54 views

Writing openSUSE image to SD card

I am releatively new to linux and I have assembled a raspberry PI 2 model B and I'm relavively unexperience with linux. I have tinkered in the past with SUSE and want to start doing it again. I have ...
1
vote
0answers
20 views

Caldera Debian Keyboard Output Chinese Characters

So, I'm an involuntary IT guy at my current position, and we have come across an issue with Caldera's flavor of Debian Linux. For some reason, with no real prompting, our keyboard starting typing ...
1
vote
1answer
20 views

Help about CentOS 7 apps & Driver [closed]

I'm using pc for several years but never tried Linux so I'm quite noob in this field. I'm using Autodesk maya, Nuke & will learn houdini very soon. I found that linux works faster for this apps so ...
2
votes
1answer
32 views

Can one core on a multicore linux system be dedicated to one user-space app?

Can a core be dedicated to one user-space app (e.g. for the purpose of bit-banging GPIO without any interruptions)?
4
votes
1answer
1k views

One host, two virtual machines that cannot ping each other. How to solve

We have Virtual Machines operating within the KVM environment. We setup one as a dev server running Apache etc., and the other as a Windows development environment. The two environments are setup ...
1
vote
1answer
540 views

Does sync command remove the dirty cache in the memory?

I am aware that sync command flushes the dirty cache into disk. I have run free command first, then sync, and then free again. The result of latter free command shows more free memory available than ...
17
votes
3answers
33k views

How to use GoToMeeting in Linux

My employer wants me and the team of developers to communicate with them using gotomeeting.com service. Is it possible to use GoToMeeting in Debian? I know that officially GoToMeeting supports only ...
1
vote
1answer
22 views

problem with upstart

Hi i got always an error message that my upstart script doesnt start. start: Job failed to start My script is: description "Tagger Version 2" start on runlevel [2345] stop on runlevel [!2345] ...
19
votes
2answers
37k views

What does aux mean in `ps aux`?

ps aux seems to conveniently list all processes and their status and resource usage (Linux/BSD/MacOS), however I cannot comprehend the meaning of parameter aux using man ps. What does aux mean?
0
votes
1answer
31 views

what does mean by HardwareCorrupted, DirectMap4k, DirectMap2M fields in “/proc/meminfo” file of Linux?

I am looking for description of following terms: HardwareCorrupted, DirectMap4k, DirectMap2M fields in "/proc/meminfo" file of Linux. I could find the following description for the fields from ...
0
votes
0answers
24 views

Echo n-values for 1 key in ansible?

I have an ansible var : site1: - name: myName value1: something1 value2: apple value3: 14 ... valuen: "a submarine" So the point is, that I don't know how many values are ...