Ubuntu is a Linux distribution with an emphasis on ease of use and installation. Note that http://askubuntu.com is specifically dedicated to Ubuntu questions.

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7answers
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Finding files that use the most disk space

Is it possible to list the largest files on my hard drive? I frequently use df -H to display my disk usage, but this only gives the percentage full, GBs remaining, etc. I do a lot of data-intensive ...
17
votes
2answers
4k views

Can I unfreeze bash or vim when SSH session freezes from timeout? [duplicate]

When my SSH session times out, the whole terminal freezes. Is there any way to break out of that connection? CTRL+C doesn't cut it.
17
votes
3answers
16k views

Overflow /tmp mounted when there is free space on /

I recently faced an "overflow" issue on /tmp. I don't have a separate /tmp partition, and there is 17% free in / – then why did I get an overflow tmp filesystem? # /etc/fstab: static file ...
17
votes
1answer
7k views

What happens in each step of the Linux kernel-building process?

I've read many tutorials about how to build custom kernels and boot Ubuntu using those kernels, and successfully followed the guides and booted custom kernels, but I have no understanding about what ...
17
votes
2answers
116k views

How to recover files I deleted now by running rm *? [duplicate]

By mistake I ran rm * on the current directory where I created many c program files. I had been working on these since morning. Now I can't take out again the time that I spent since morning on ...
17
votes
3answers
7k views

Are multiple @daily crontab entries processed in order, serially?

I want two jobs to run sometime every day, serially, in exactly the order I specify. Will this crontab reliably do what I want? @daily job1 @daily job2 I'm assuming they run one after the other, ...
16
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4answers
13k views

Mount a filesystem read-only, and redirect writes to RAM?

Is it possible to mount a loopback file as read-only, and redirect all writes to RAM?
16
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2answers
6k views

Why is vi apparently broken (viminfo error E576), and how can I fix it?

I am proficient at using Unix/Linux, but I am not an expert. If I want to open a file (for example, file.txt), I use vi: vi file.txt This opens the file, and if I want to close it, I use :q!. I ...
16
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1answer
8k views

What does a kernel source tree contain? Is this related to Linux kernel headers?

In books, I typically read references to the Linux Source Tree at /usr/src/linux with the usual set of subdirectories (arch, block, crypto, ...). I was expecting this tree to contain the binary files ...
16
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1answer
13k views

How do I set a user's default .bashrc file?

On Ubuntu 10.4 I have edited the /etc/bash.bashrc file to set some variables like the command history size (HISTSIZE=5000), however if I create a new users Ubuntu by default gives them a .bashrc file ...
16
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2answers
2k views

Vulnerability demonstration on Ubuntu 9.04

For a class on IT security, I want to demonstrate privilege escalation to the students. To do so, I looked through the exploit/linux/local list in the Metasploit Framework, finding (among others) ...
16
votes
3answers
24k views

How to boot EFI kernel using QEMU (kvm)?

Hey guys I'm trying to emulate a EFI enviroment using QEMU (kmv), virtualbox takes 15 minutes to boot in EFI mode using archboot. Using legacy BIOS mode I can boot using this command: root@...
15
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3answers
117k views

How to get IP Address using shell script? [duplicate]

Want to get the IP address using Shell script. Without knowing the eth0 or eth1 or eth2 How to get the particular IP address. I am not interest to get localhost address, want to get private IP ...
15
votes
2answers
186k views

Recovering from 'grub rescue>' crash [closed]

Originally posted to AskUbuntu.com ... AskUbuntu has adopted a policy of closing questions about EOL (End Of Life) versions. There's a vocal contingent to remove them as well. To prevent ...
15
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5answers
10k views

How is sudo set to not change $HOME in Ubuntu and how to disable this behavior?

On Ubuntu 12.04, when I sudo -s the $HOME variable is not changed, so if my regular user is regularuser, the situation goes like this: $ cd $ pwd /home/regularuser $ sudo -s # cd # pwd /home/...
15
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3answers
20k views

Linux, disable /dev/fd0 (floppy)

Is it possible to make Linux kernel completely ignore the floppy disk controller? I do not have the drive but obviously my motherboard does contain the controller. I would like to disable the /dev/fd0 ...
15
votes
4answers
20k views

How can I track who SSH'es into my linux machine?

I'm running Ubuntu 10.04. Is there a way I can get a daily report of who has logged onto the box, what time, and even - this may be asking too much - a report of the commands they used? This is a low-...
15
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3answers
27k views

How to configure external IP addresses for LXC guests?

I'm exploring the LXC features in Ubuntu 12.04 and I really want to set up a network like this: client1: 192.168.56.101/24 lxc-host: 192.168.56.102/24 guest1 192.168.56.201/24 guest2 192....
15
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5answers
22k views

Why doesn't docker container start at boot w/ upstart script on Ubuntu 12.04?

Using instructions for Docker auto-start on Linode VPS running Ubuntu 12.04 and Docker 0.8.1, the specified container does not start on reboot. Once booted, I am able to ~$ sudo start [service-name] ...
14
votes
4answers
3k views

Is there a way to auto turn-on Ubuntu?

Like a command line or a small piece of software I know that there are many ways to auto-shutdown, but I'm concerned about auto-turn-on.
14
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3answers
2k views

How can I de-fragment a drive using Ubuntu?

Is it necessary to defrag drives in Ubuntu? If so, how do I do it and how often should it be done?
14
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4answers
533 views

What specific vulnerabilities am I creating by disabling the sudo password?

Here are some instructions on how to disable your sudo password. These carry the following warning If you disable the sudo password for your account, you will seriously compromise the security of ...
14
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5answers
24k views

Can't apply chmod to a file

I have a file on my HDD, cd /media/celebisait/5AC69788C6976355 There is my file called myFile.tar.gz. I do als -l, -rw------- 2 celebisait celebisait 1387745311 Jun 6 2013 myFile.tar.gz ...
14
votes
3answers
9k views

l, ls & la — what are the differences, and are there more of these commands?

So, through typing several commands I've found that there's not only ls, but l and la too. There doesn't appear to be any man entries on Ubuntu 12.14. They all appear to do similar things with minor ...
14
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7answers
3k views

Can I label a disk device rather than a partition?

I know about the e2label and friends program for attaching a label to a disk partition e.g. e2label /dev/sda1 bla What I want to do is something different: I want to create a label for a hard drive,...
14
votes
3answers
13k views

What is the proper way to manage multiple python versions?

I have a machine with Python 2.6 installed as the default Python. Then, I installed Python 2.7, and manually created /usr/bin/python as a symlink to the new installation. Then, I was running into ...
14
votes
1answer
28k views

How to permanently disable a network interface?

I've brought down a network interface with ifconfig wlan0 down, but every few hours or so, the wlan0 interface comes back up and I can't figure out why. I don't restart the machine, never changed /...
14
votes
2answers
18k views

How can I make this daemon/init run as a non root user?

I have an init script to kick off a daemon. The problem is it runs as root. I would like it to run as a user called "deploy". Ubuntu 12.04 #! /bin/sh # File: /etc/init.d/unicorn ### BEGIN INIT ...
14
votes
1answer
6k views

Installing two glibc alongside in debian/ubuntu

Is it possible to install and use two different glibc versions on the same machine. Where one version is only used to run legacy software, which relies on old glibc binaries? Is it possible to do ...
13
votes
6answers
2k views

Is there a root password on OS X and Ubuntu?

When you setup a new Ubuntu or OS X installation a user is generally created for you. On OS X it is whatever username you pick. On Ubuntu (the server version) usually the ubuntu user is created. The ...
13
votes
7answers
18k views

Linux equivalent for Windows Startup

Is there any way to add an application/script to the Linux startup so every time the system is on it executes [i'm looking for some automated way, user should not add this by cron job or something ...
13
votes
4answers
9k views

/etc/rc.d vs /etc/init.d

Is ubuntu's /etc/init.d directory exactly equivalent (functionally) to what I presume to be the more standard /etc/rc.d/ (at least on arch)? Is there any particular reason canonical used init.d ...
13
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4answers
794 views

Monitor hard disk activity

In a Ubuntu 14.04 server I am experiencing a massive hard disk activity which has no apparent justification: it comes as a burst, it lasts a few minutes and then disappears. It consumes system ...
13
votes
2answers
10k views

Installing mysql-server in vagrant bootstrap shell script (how to skip setup?)

I did try to install mysql-server on my Vagrant Ubuntu 12.04 LTS virtual machine. When I did so, the setup auto-starts. I can see this in the Vagrant output: While not mandatory, it is highly ...
13
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4answers
32k views

How to find out if Ubuntu is using DHCP (Ubuntu 12.04 LTS GUI)

How can I find out if my IP address is DHCP, Fixed or Dynamic? I need to tell my network administrator what the IP address is, that my Virtual Machine is using. I know the numbers, but I don't know ...
13
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4answers
2k views

In Debian based systems, how do we purge configuration files of packages that have already been uninstalled?

To be more specific, I would like to do the equivalent of adding the --purge flag to the following command sudo apt-get autoremove --purge [package name] to packages that are no longer on the ...
13
votes
4answers
7k views

How to /dev/null background processes “informational” output?

[USER@SERVER ~] sleep 3 & [1] 5232 [USER@SERVER ~] [1]+ Done sleep 3 [USER@SERVER ~] How do I /dev/null these two messages?: [1] 5232 [1]+ Done sleep ...
13
votes
1answer
4k views

Using Atlas from scipy

I installed Ubuntu 12.04 64 bit. I need to work with python and scipy, I installed them and when I run the test: python -c "import scipy; scipy.test()" I get the message: ImportError: libatlas....
13
votes
4answers
21k views

XFS vs Ext4 vs Others - which file system is stable, reliable, for long run such as 24/7 case [closed]

XFS and Ext4 file system which one is really stable and reliable for long run with heavy disk write and read? the system will be used in a place where 24/7 is in service, and every second there is ...
13
votes
4answers
14k views

I changed my hostname, why is my bash PS1 prompt unchanged

I changed my hostname by editing /etc/hostname and can see the new hostname using the hostname and hostname -F commands. But the shell prompt is still showing the old hostname. This is Ubuntu 11.0.4 ...
13
votes
4answers
12k views

How to get rid of the “scanning for btrfs file systems” at start-up?

After upgrading from Ubuntu 12.04 to Ubuntu 12.10, I get a message "scanning for btrfs file systems" at starting-up. I don't have any BTRFS filesystem. It delays the booting for about 15 seconds. How ...
13
votes
2answers
2k views

Is it possible to simulate installation of Debian packages, still marking them installed?

Here's what I would like. Start with a virtual system with no installed packages. Then I invoke a tool similar to apt-get to ask it to compute the dependencies and mark all the packages that would be ...
12
votes
2answers
46k views

Where does postfix store email?

I can't find any documentation on how postfix stores email. Where is it stored, and in what format? I'm using Ubuntu server 11
12
votes
6answers
33k views

Where is Netbeans installed on Ubuntu?

I installed Netbeans on my Ubuntu 11.10 machine. I used the combined method, so Netbeans and JDK are installed from a single file. However, now that it's installed I can't figure out how to start ...
12
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5answers
693 views

Is there a more succinct alternative to piping to wc for counting files in a directory

If I do ls -1 target_dir | wc -l, I get a count of files in a directory. I find this a bit cumbersome. Is there a more elegant or succinct way?
12
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5answers
27k views

Can a linux user change their password without knowing the current password?

I'm setting up a few ubuntu boxes, and using opscode's chef as a configuration tool. It would be fairly easy to install public keys for each user on each of these servers, and disable password ...
12
votes
4answers
16k views

'mv' equivalent of drag and drop with replace?

In a GUI environment, a drag-and-drop with replace will replace files and entire directories (including contents) with whatever is being copied in. Is there a way to accomplish this same intuitive ...
12
votes
2answers
3k views

How to implement package install suggestion on Debian?

I have noticed that while on Ubuntu, if I type the following: mc and it isnt installed, I get the message below: The program 'mc' is currently not installed. You can install it by typing: sudo apt-...
12
votes
3answers
6k views

Why don't my arrow keys work in sh?

I recently installed Ubuntu and when I run sh on the Terminal my arrow keys don't work so I can't go through my call history or edit whatever I'm typing. It just comes out as weird characters like ^[[...
12
votes
1answer
357 views

Partitioning done incorrectly?

Long story short, we had issues installing linux on this system. It magically decided to work, but now I'm unsure about the hard drive partitioning. One hard drive has linux installed on it and the ...