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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0
votes
3answers
54 views

crontab is launching multiple java process every 5 minutes?

I have a java runnable jar which I need to run it if it not running or got killed for some reason so I decided to use crontab for this - I need to run the crontab as "poppetapp" user so I am logged ...
1
vote
1answer
16 views

I need dhclient to flush IP address/routes when link goes down

I am running one Ubuntu Server 14.04 with network configuration using /etc/network/interfaces and so ifup/ifdown scripts. I realised that if I configure one interface in DHCP mode, then I unplug the ...
8
votes
10answers
6k views

linux diff tools: create list of modified files

How do I create a list of modified files programmatically using linux command line tools? I'm not interested in the difference in any particular file (delta, patch). I just want to have a list of new ...
6
votes
3answers
20k views

How do I identify which Linux distro is running? [duplicate]

We have some new hardware in our office which runs its own customized Linux OS. How do I go about figuring which distro it's based on?
1
vote
2answers
9k views

apt-get install fails with error “Unable to locate package”

Background Hi there. I'm relatively new to linux so you'll have to excuse my noobie question. I'm trying to follow the instructions found here: http://repo.pouf.org/ to install kamailio on my ...
0
votes
0answers
48 views

Terminal Emulator with CTRL+Scroll Zoom

Are there any Linux Terminal Emulators that offer "control & scroll zoom" (allowing you to adjust the visible size of fonts by holding down ctrl and scrolling your mouse-wheel)? Recently on ...
-1
votes
0answers
32 views

How to write shell script to check diskspace on the list of servers and store it in a file?

I want to write the shell script that checks the disk space for the list of servers and store the output in a file. Then add the entry in the cronjob to execute the script. And finally I want the ...
2
votes
0answers
131 views

Virtualbox guest responding really slow over SSH, VBoxHeadLess stuck in 99.9% system time

I've been using Vagrant/virtualbox on a relatively new laptop with decent specs (16GB memory, Intel i7 4710HQ cpu, dual m-sata SSD). So far, with every guest I run, I encounter really high latency, ...
5
votes
2answers
1k views

Querying an overlayfs

I'm looking for a way to query a mounted overlay filesystem (overlayfs) in order to check it's upper and lower directory, but until now I haven't found any suitable command for that. Is there is a way ...
1
vote
0answers
25 views

Is here any 100% solution how to run 3 monitors (2 nvidia + 1 iGPU) with drivers? [closed]

I have 2 monitors on my Nvidia card and 1 on integrated Intel Graphics I wasted a lot of time to this problem. After install Intel drivers works only monitor on IGPU, after Nvidia only on Nvidia card. ...
2
votes
1answer
83 views

Unexpected processor/core counts for AMD processor

I wanted to determine if a machine has hyperthreading enabled or not. To determine this, I used advice I found online, which operates as follows: physical_proc_count = `grep "physical id" ...
0
votes
6answers
47 views

How can I use grep to search only on the first line of files for a specific string?

How can I use grep to find a string in files, but only search in the first line of these files?
0
votes
0answers
16 views

Looking for script to fetch output for requested date [closed]

I am looking for a script which helps me to fetch output for requested timestamp from different directries.
1
vote
1answer
899 views

Build Linux and run it (uImage) on the Beagle board - xM

I'm working on some project where I'm using the Beagle board - xM Rev C. Power supply is 5V/2A adapter. My task is porting Linux Angstrom on the board but I have some problems. I have choosen Linux ...
1
vote
1answer
35 views

index in front of “ip link” or “ip addr” output

There is an index in front of each network interface in ip link show or ip addr show output. For example from 1 to 6 here: root@T42:~# ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc ...
0
votes
0answers
9 views

Linux Mint & LIFEREA rss reader

I have the linux Mint 17.1 Cinnamon distribution installed on my laptop and I cannot launch the software Liferea from the terminal, although, it will work fine if I launch that using the menu/icon. ...
1
vote
1answer
32 views

How do I run a program without network access? [duplicate]

I am making a program that scrapes information from some web services. I want to test how my program reacts when it can't reach the web service, like if the web service is down or if the local ...
1
vote
2answers
51 views

Is zswap eligible to reduce swap IO?

Does zswap compress pages, that are written to the swap device? Is it eligible to reduce swap IO?
0
votes
1answer
18 views

How do I install freeBSD headers ?

I have been a arch linux user for the past 2 years and now moving on to freeBSD for kernel development. I have install freeBSD and want to compile a dynamically loadable kernel module for freeBSD. ...
2
votes
1answer
30 views

set MAC address in “interfaces” file without configuring other network parameters

Under Debian Wheezy permanent network configuration takes place in /etc/network/interfaces file. Is it possible to configure hwaddress for an interface without configuring other network parameters ...
-2
votes
0answers
23 views

Linux command inside C code: /* treat as comment? [migrated]

In C, I want to run linux command. Namely, int status; status=system("lftp ftp://192.168.1.1 -e "mget -E /2015/Date*/*Snap/*.csv"); The * above is wildcard matching. The C compiler thinks this is ...
-1
votes
0answers
87 views

Unable to get vmware shared folders working in Ubuntu 14.10 Guest

i Installed Ubuntu 14.10 64Bit in VMWare Workstation 10.0.5 within windows 8.1 Enterprise. I installed vmware tools by running the vmware-install.pl script in terminal.But I am Getting an error ...
2
votes
3answers
1k views

How to determine bitness of hardware and OS?

Output of uname -a on my RHEL 5.4 machine is: Linux <machine name> 2.6.18-164.el5 #1 SMP Tue Aug 18 15:51:48 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux Does it mean that hardware is 64 bit ...
2
votes
1answer
38 views

What prevents a reboot?

On Linux, how can I track what prevents a reboot of the system after issuing it via sudo reboot? I always thought that this caused switching the runlevel and in the end the reboot, but now I was ...
3
votes
1answer
2k views

Kernel booting stops right after “Uncompressing Linux…”

I'm trying to bring up an ARM-based board. I've got U-Boot working but can't seem to get the kernel to load. Most of the time it only goes as far as: Starting kernel ... Uncompressing Linux... A ...
1
vote
0answers
26 views

Retrieve device manufacturer without sudo

I need to retrieve the manufacturer model of a linux device (laptop or desktop). I saw that you could use dmidecode | grep -A3 '^System Information' but it needs admin rights. There is any way to do ...
17
votes
4answers
5k views

Why does dd from /dev/random give different file sizes?

I am running the following command on an ubuntu system: dd if=/dev/random of=rand bs=1K count=2 However, every time I run it, I end up with a file of a different size. Why is this? How can I ...
3
votes
2answers
3k views

How to measure on Linux the peak memory of an application after has ended

How do I measure the peak memory of an application running on Linux? I run this app in batch so I cannot use RSS since, it reports the current memory. I need the peak memory that the application has ...
1
vote
0answers
45 views

add user to group [closed]

Correct way for add an user to group should be something like this: usermod -a -G groupName userName sometimes (for speed amd comfort) I prefer editing /etc/group and manually add users to ...
3
votes
2answers
238 views

Why is it that my initrd only has one directory, namely, 'kernel'?

I'm using debian live-build to work on a bootable system. By the end of the process i get the typical files used to boot a live system: a squashfs file, some GRUB modules and config files, and an ...
3
votes
1answer
743 views

cleaning /dev/md0 filesystem ( raid)

I have a CentOS server using raid. The /proc/partitions contains: major minor #blocks name 8 0 976762584 sda 8 1 104391 sda1 8 2 921600855 sda2 8 3 55054755 ...
0
votes
0answers
16 views

Failed login notification at login

I have seen it before when you log into a Linux box wrong, when you do successfully log on, it notifies you that someone attempted to log on as you and didn't succeed. How is this accomplished? I ...
0
votes
0answers
12 views

LUKS Encrypt volumes during Pidora install on Raspberry PI

I have a Raspberry PI and I would like to LUKS encrypt all volumes during the Pidora install process, but it seems there are no options in the GUI installer to do so. I would not like to add ...
1
vote
0answers
22 views

Apache / OpenSSL configuration keywords `SSLProtocol` vs. `SSLCipherSuite`

According to the Apache docs I can configure the cipher suite with (a.o.) two different keywords and examples on Internet often use both (but not necessarily identical to below example). What is the ...
1
vote
1answer
53 views

cat .bash_history | grep ./configure [closed]

Why does this not give any output: cat .bash_history | grep ./configure on an system/in an shell where ./configure has been run multiple times. And if I use the arrow key's to scroll the history in ...
1
vote
2answers
620 views

Command/scripts to check the Reverse DNS Lookup time

I am working on a project in which one master communicates with numbers of slaves. For that it has to make connection with hosts in network. But sometimes it hangs. I think that the reason behind is ...
1
vote
1answer
443 views

port forwarding to internal lan server

I've ppp0 --> eth1 and eth0 (internal lan). I need forwarding externel 10022 port to port 8999 of the server 192.168.1.254 iptables -t nat -A PREROUTING -p tcp -i ppp0 --dport 10022 -j DNAT --to ...
0
votes
2answers
29 views

What are some practical purposes for using renice? [closed]

I'm having a hard time finding a purposeful need for using renice more often, and I would like to know if there are any scenarios in which using process prioritization and adjusting it on-the-fly has ...
13
votes
1answer
486 views

What happens when you rsync without a destination?

To make the story short, I did an rsync: rsync -avP root@exampleserver.com:/tmp/ And I forgot to put in my source directory... I really meant to run: rsync -avP /tmp/ root@exampleserver.com:/tmp/ ...
0
votes
0answers
14 views

Linux mint 17 /etc/enviroment no_proxy variable ignored by the system [closed]

I have setup some environment variable on my Linux Mint 17, to avoid that some addresses being used over my office network proxy (squid). Along with others variable I setup the no_proxy one like ...
0
votes
0answers
20 views

asking administrative permissions for remote console session while logging

Errot:to log on to this remote console session you must have administrative permissions on this computer. this error in specific Redhat system. from other systems its working.
1
vote
0answers
41 views

How to get the Adaptec 1200A to work under Linux at UDMA/100 (instead of 66)

A while ago, I got myself a used Adaptec 1200A controller card to keep my onboard slots free for easier connect/disconnect of drives and now I am wondering why this card will only operate at UDMA 66. ...
0
votes
0answers
8 views

How to set up Qmail to accept joining email list via Mailman LISTNAME-join@DOMAIN?

My configuration: CentOS 5.8, Plesk 11.0.9. I am trying to make my mailing list accept another way of joining a list. That is to join the Mailman mailing list by sending email to ...
1
vote
1answer
153 views

how to check the string is Null or not in shell script? [closed]

I had a script like this #!/bin/bash line="hello" if [ -z $line ] ; then echo "String null" fi This will work properly, but when I give the lineas follows ...
2
votes
3answers
129 views

How can I determine if a process is a system process?

I'm reading the /proc directory (or pseudo-fs) to find all processes. I'm getting the information I need from /proc/[pid]/status but there's something else I need. Is there any way to figure out which ...
1
vote
2answers
982 views

ping: unknown host with iptables enabled

I can't ping www.google.com. However I can ping the IP address: ping 74.125.237.142 At first, I thought it is a problem with my DNS settings. But I checked my resolv.conf, hosts, and hostname ...
0
votes
1answer
14 views

Why does aptitude markauto uninstall my package?

From the aptitude help: aptitude 0.6.8.2 Usage: aptitude [-S fname] [-u|-i] .. snip .. markauto - Mark packages as having been automatically installed. unmarkauto - Mark packages as having ...
0
votes
1answer
3k views

Cannot dual-boot Linux Mint and Windows 7

I have Windows 7 already installed from a long time ago and I have no Windows/update CD. I want to install Linux Mint. I created a partition, formatted it as Ext4 (in Linux), and labeled it E. I ...
50
votes
3answers
84k views

How do you empty the buffers and cache on a Linux system?

Prior to doing some benchmarking work how would one free up the memory (RAM) that the Linux Kernel is consuming for its buffers and cache?
2
votes
0answers
34 views

Persistent configuration of two screens

I want to configure two screens side by side and want the configuration to persist a system restart. (I'm using xfce on Xubuntu 12.) I've inspected old questions and the answers mentioned arandr and ...