Ubuntu Linux is a Debian derivative that aims to bring Linux mainstream. Questions on this site should generally refer to Ubuntu Server. Note that http://askubuntu.com is specifically dedicated to Ubuntu questions.

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What is the difference between sudo -i and sudo su -

What is the difference between commands sudo -i and sudo su -? Are they the same?
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3answers
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How to setup a MySql server to accept remote connections?

I am installing a MySql server in Ubuntu desktop. I could connect MySql Query Browser to it when specifying the Server Hostname as localhost, but when I replace it by the machine's IP it stops working ...
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6answers
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How to grant temporary access to server?

I've hired a remote consultant to tune up my servers. Now, I am not 100% confident about giving him root password and allow him to do whatever he wants to do on the servers. Ideally, I want to see ...
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2answers
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Directory in /var/run gets deleted after hard reboot

I keep my sphinx pid in /var/run/sphinx/searchd.pid but every time I hard reboot the directory /var/run/sphinx disappears and sphinx fails to start. Is there a way to make that directory stick or ...
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4answers
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How do limit disc i/o during backup?

I have a cron that basically do a simple "tar zcf" in the night. The server has: 8 Cores - Intel(R) Xeon(R) CPU E5606 @ 2.13GHz 25GB RAM Ubuntu 12.04.2 LTS Hardware RAID 1 (LSI Logic / Symbios ...
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4answers
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Unable to install mysql-server in Ubuntu

I am unable to install mysql-server on my ubuntu 9.10 server machine. When using apt-get install mysql-server the output is : # apt-get install mysql-server Reading package lists... Done Building ...
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7answers
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How to remotely install Linux via SSH?

I need to remotely install Ubuntu Server 10.04 (x86) on a server currently running RHEL 3.4 (x86). I'll have to be very careful because no one can press the restart button for me if anything goes ...
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2answers
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Where is initdb in Ubuntu

I want to reset my postgresql database back to its initial condition after install. Apparently initdb is the way to do this, but although the command has a man page, it doesn't seem to be anywhere on ...
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3answers
475 views

Putting /etc under source control

I would like to put my /etc directory iunder source control using bazaar. Are there any gotchas in doing this. It seems safer to do it user an ordinary user rather than root - might there a be a ...
14
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3answers
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what is sensible-mda and do i need it?

I'm running Ubuntu Intrepid, and have been seeing the following my logs: Aug 23 16:01:03 wp1 sm-mta[13700]: n7NFJIad013566: Warning: program /usr/sbin/sensible-mda unsafe: No such file or directory ...
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5answers
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Dovecot vs Courier vs Cyrus [closed]

What is best for a Personal/SMB mail server running on an Ubuntu Server (8.04+)? I want to setup my own mail server at home to evaluate some options for my company before I make a recommendation. ...
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3answers
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MySQL: How do I get my “Maximum possible memory usage” down?

I've recently been having problems with thrashing as a result of running out of memory. (My VPS has 256M total) I'm trying to tune MySQL using mysqltuner.pl, and get the following results: -------- ...
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2answers
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How can I get Jenkins to stop listening for remote connections?

I have Jenkins sitting behind Nginx, with Nginx taking care of authentication, but Jenkins is still listening on port 8080 externally, so by accessing the box on port 8080 people can bypass Nginx. ...
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5answers
29k views

Setting up RADIUS + LDAP for WPA2 on Ubuntu

I'm setting up a wireless network for ~150 users. In short, I'm looking for a guide to set RADIUS server to authenticate WPA2 against a LDAP. On Ubuntu. I got a working LDAP, but as it is not in ...
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3answers
38k views

Iptables: How to allow only one ip through specific port?

How can I on my ubuntu server, in Iptables only allow one IP adress on a specific port? Thanks
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6answers
11k views

pam service(sshd) ignoring max retries

I have vps that I use to run a webserver on, it currently runs ubuntu server 12.04. Since a few weeks I keep getting a lot of errors in my ssh console. 2014 Apr 11 08:41:18 vps847 PAM service(sshd) ...
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3answers
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Apache “Client denied by server configuration”, despite allowing access to directory (vhost configuration)

in Apache on Ubuntu I've set up a vhost, but in the browser I keep getting a "403 Access forbidden" error; the log says "Client denied by server configuration: /home/remix/". Looking for the solution ...
13
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3answers
526 views

Which method to use for granting sudo

What is the difference between adding a user to /etc/sudoers and usermod -a -G sudo? Which method should be used for granting sudo?
13
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4answers
19k views

How to run script via SSH that doesn't end when I close connection?

I need to run script, that takes long time to execute, or I just want it to run forever. I can't just SSH to my machine, because when I disconnect it stops running. Is there any way to run script ...
13
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2answers
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Linux e1000e (Intel networking driver) problems galore, where do I start? [closed]

I'm currently having a major problem with e1000e (not working at all) in Ubuntu Maverick (1.0.2-k4), after resume I'm getting a lot of stuff in dmesg: [ 9085.820197] e1000e 0000:02:00.0: PCI INT A ...
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5answers
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Fixing services that have been disabled in /etc/default/ with puppet?

I'm using puppet to (theoretically) get npcd to start upon installation, however on Ubuntu, that service comes installed with the default setting in /etc/default/npcd of RUN="no": $ cat ...
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5answers
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console-kit-daemon - can it be stopped?

I have 60 instances of Console Kit daemon on Ubuntu 9.04 server installation. Is it safe to kill those or stop these processes. They seem to be taking about 20% of RAM each(see on htop).
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3answers
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Alternatives to apache benchmark? [closed]

I'd like some tools for ubuntu that I can use to test my server, how much it can handle. Any suggestions? I've used apache benchmark before, but I'd like to try out something else. (As a side ...
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2answers
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Why does Debian clean php sessions with a cron job instead of using php's built-in garbage collector?

Debian and derivatives (Ubuntu) don't use the php session garbage collector session.gc_probability = 0 instead they use a cron /etc/cron.d/php5 09,39 * * * * root [ -x /usr/lib/php5/maxlifetime ] ...
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5answers
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How can I configure unattended installation of Ubuntu?

I'd like to configure an installer for Ubuntu which runs in 'unattended' mode and answers all the questions with defaults or pre-configured settings. Ideally it should run and reboot on it's own, ...
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5answers
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ubuntu servers - what do i need to do to keep it uptodate

I am setting up an ubuntu server and want to know what I should be doing on it regularly. apt-get update/upgrade seems obvious. Is there a glsa check for example? Anything else I should be running? ...
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3answers
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max files per directory in ext4

I manage an application that contains a filestore in which all the files are stored with the filenames equal to their md5 sums. All files are stored in one directory. Currently there are thousands, ...
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3answers
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How to fix “BUG: soft lockup - CPU#0 stuck for 17163091968s”?

UPDATE: I updated the title of the message, because I've recently seen more of these problems with this exact time amount of 17163091968s. This should help people investigating the symptoms to find ...
13
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1answer
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Multiple php versions simultaneously on Ubuntu

I want to be able to run multiple php versions on my development box running Ubuntu 12.04. What I want to accomplish is that when I use localhost as domain a default is used (let's say php 5.3.17). ...
12
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7answers
26k views

df says disk is full, but it is not

On a virtualized server running Ubuntu 10.04, df reports the following: # df -h Filesystem Size Used Avail Use% Mounted on /dev/sda1 7.4G 7.0G 0 100% / none ...
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3answers
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How to make folders 00-99 with a single command in Ubuntu?

I need to create folders starting from 00 to 99 (00, 01, 02, 03, etc....) in several hundred places. Is there a single line command that will let me do that?
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6answers
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How to force MySQL to connect by TCP instead of a Unix socket?

I would like to analyze mysql traffic. Right now, all mysql requests are sent to the MySQL unix socket: unix 2 [ ACC ] STREAM LISTENING 3734388 15304/mysqld ...
12
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3answers
853 views

grep behaving differently on Fedora vs Ubuntu

So when I run this in Fedora I'm seeing this: $ ls hmm_data/indivA12_AATAAG/refs/par1/ 2R-orths.alleles 2R-ref.alleles $ ls hmm_data/indivA12_AATAAG/refs/par1/ | grep -F '-ref.alleles' ...
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3answers
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How to convert 'dmesg' time format to 'real' time format

I have (for example) this log entry in dmesg output: [600711.395348] do_trap: 6 callbacks suppressed Is there a possibility to convert this 'dmesg' time to 'real' time to know, when this event ...
12
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8answers
11k views

Should I completely turn off swap for linux webserver?

Recently my friend told me that it is a good idea to turn off swap on linux webservers with enough memory. My server has 12 GB and currently uses 4GB (not counting cache and buffers) under peak load. ...
12
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9answers
18k views

How can I find the biggest directories in unix / Ubuntu?

Is there a way in Unix to see the biggest directories on disk ? I need to know why I'm almost done with the space on the server, and I dunno where most of the space is used.. thanks
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4answers
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Can dpkg verify files from an installed package?

With rpm -qV openssh-server I will get a list of files that have changed compared to default. ~$ rpm -qV openssh-server S.?....T. c /etc/ssh/sshd_config ~$ Can dpkg on Ubuntu do the same?
12
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3answers
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How to get - number of threads per process?

This is one Ubuntu 9.10 server. Also how to see memory usage per process? Thanks
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4answers
8k views

What is vmlinuz and why do I care?

I just got a network alert that I've never seen before, on one of the few Ubuntu boxes that we have: The following monitoring trigger has been fired: /vmlinuz has been changed on server XXXXX: ...
12
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1answer
16k views

How to configure Tomcat to only listen to 127.0.0.1?

The environment is Ubuntu 10.04.1 LTS running Tomcat 6 and Apache 2.2 from the repos. Apache is configured to proxy requests to Tomcat, so I really want to turn off Tomcat listening to requests on ...
12
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5answers
13k views

Recover from shutdown during Ubuntu distribution upgrade

I have a computer which was unexpectedly shut down during a distribution upgrade (Ubuntu 8.10 -> 9.04). It now won't finish booting - various X errors, then it goes to the login screen but won't ...
12
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4answers
5k views

Ubuntu's garbage collection cron job for PHP sessions takes 25 minutes to run, why?

Ubuntu has a cron job set up which looks for and deletes old PHP sessions: # Look for and purge old sessions every 30 minutes 09,39 * * * * root [ -x /usr/lib/php5/maxlifetime ] \ ...
12
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3answers
14k views

Why is Apache running so many processes? Excessive RAM here?

I notice Apache is running multiple processes on my LAMP server (ubuntu 10.10). I'm just running a Wordpress site with MySQL as a database. It seems like www-data is running apache2 more than it ...
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11answers
8k views

What creates CPU I/O wait but no disk operations?

I have CPU I/O wait steady around 50%, but when I run iostat 1 it shows little to no disk activity. What causes wait without iops? NOTE: There no NFS or FUSE filesystems here, but it is using Xen ...
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7answers
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Out of disk space, what's the source?

Filesystem Size Used Avail Use% Mounted on /dev/sda1 220G 220G 0 100% / none 1.9G 168K 1.9G 1% /dev none 1.9G 0 1.9G 0% ...
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4answers
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Ubuntu/Debian: Show list of available versions of a specific package

Sorry, this might be a beginner question: How can I list all available versions of specific package? I know with apt-get install myPackage=1.2.3 a specific version could be installed. And with ...
12
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3answers
28k views

Soft limit vs Hard limit?

Can anyone explain in layman's terms what the difference between soft and hard limit is? Should I set my soft and hard limit to be the same? Or should soft be significantly lower? Does the system ...
12
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3answers
14k views

Starting network connection from Ubuntu recovery?

I tried to upgrade Ubuntu from Hardy to Intrepid last night, and seem to have killed it. I can boot into "recovery mode" and the root shell, but it freezes when it tries to start the Gnome ...
12
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4answers
13k views

How can I configure a private (friends only) IRC Server?

I am trying to setup an IRC server on my machine for a bunch of friends and me to use. This is an ubuntu box and I have installed dancer-ircd and dancer-services and gotten everything up and running ...
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20answers
1k views

Are there any reasons NOT to run an Ubuntu server?

I'm going to be setting up a network for a small office soon. The network will consist of about 5 workstations (soon to be more) and 2-3 servers (one "real" server and a couple ...