Questions tagged [ubuntu]

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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5 answers
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associate name with ip for ssh?

Let's say I just have an ip address for a server and I don't have a domain with it (it's just a database server, so it doesn't need a domain). I don't want to have to remember the ip address every ...
Matthew's user avatar
  • 1,917
63 votes
7 answers
114k views

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 ...
Jan Marek's user avatar
  • 2,200
63 votes
4 answers
56k views

Purpose of Debian "sites-available" and "sites-enabled" directories?

Can anyone tell me—in a nutshell—what the purpose of these two directories are in Debian? /etc/apache2/sites-enabled /etc/apache2/sites-available I notice that diffing sites-available/000-default ...
aaaidan's user avatar
  • 732
63 votes
2 answers
45k views

debian packages version convention

I'm using debian/Ubuntu, and get confused about versions of packages. When using dpkg -l command, I get: ii vim 2:7.3.429-2ubuntu2.1 Vi IMproved - ...
cizixs's user avatar
  • 933
62 votes
5 answers
39k views

How can I check /dev/xvda1?

On login to EC2 (Ubuntu) instance, I see *** /dev/xvda1 should be checked for errors *** I can't fsck /dev/xvda1 because it is mounted, and sudo umount /dev/xvda1 fails because it is in use. lsof ...
user1836587's user avatar
62 votes
5 answers
85k views

How do you use apt-get to only install critical security updates on ubuntu?

How do you use apt-get to only install critical security updates on ubuntu? We'd like to only upgrade packages that need to be upgraded for security reasons, without upgrading all other packages.
readonly's user avatar
  • 3,429
62 votes
2 answers
153k views

Where are the logs for ufw located on Ubuntu Server?

I have an Ubuntu server where I am blocking some IPs with ufw. I enabled logging, but I don't know where to find the logs. Where might the logs be or why might ufw not be logging?
blockhead's user avatar
  • 881
61 votes
10 answers
101k 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 out of space on the server,= and I don't know where most of the space is used.
aneuryzm's user avatar
  • 1,754
60 votes
7 answers
198k views

adding password to .ssh/config [closed]

I'm using ubuntu 12.04. I'm using ssh for connecting to many servers daily, so I put their parameters in .ssh/config file; like this : Host server1 User tux Port 2202 HostName xxx.x.xx.x I know we ...
Ajo Augustine's user avatar
60 votes
7 answers
33k views

Given a debian source package - How do I install the build-deps?

I have a debian (well technically ubuntu) source package, i.e. the .dsc, the .tar.gz, etc., I want to build this. The dpkg-buildpackage fails, since I don't have all the build dependencies. Normally ...
Amandasaurus's user avatar
  • 32.3k
60 votes
4 answers
204k views

nginx without server_name and using only static ip address?

this is my first web app deployment and am running into all sorts of issues. I am currently going for a nginx + gunicorn implementation for the Django app, but mostly this question relates to nginx ...
bash-'s user avatar
  • 847
60 votes
3 answers
122k 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 ...
kidcapital's user avatar
59 votes
8 answers
121k views

Apache: SSLCertificateKeyFile: file does not exist or is empty

I am configuring SSL for Apache 2. My system is Ubuntu Server 10.04 LTS. I have the following settings related to SSL in my vhost configuration: SSLEngine On SSLCertificateKeyFile /etc/ssl/private/...
blueFast's user avatar
  • 4,330
59 votes
1 answer
4k views

Can't enter the letter 'e' over ssh [duplicate]

Right now I am experiencing some very, very weird behaviour on a Ubuntu 14.04.2 LTS server I am managing. Connecting to the server over ssh either from cygwin(mintty) or a terminal on a Linux machine,...
Zulakis's user avatar
  • 4,233
59 votes
2 answers
72k views

How do view older journalctl logs (after a rotation maybe?)

I am running docker on ubuntu 16.04 and would like to view the logs. However, I am unable to view logs after what I am guessing is some sort of rotation or the logs grow to a certain size. I have not ...
jdf's user avatar
  • 951
57 votes
3 answers
128k views

Do I need to refresh or restart anything after I add/update a crontab in Ubuntu Server 8.04?

When you change something in Apache you need to reload or restart apache. Does anything need to be refreshed or restarted in Ubuntu Server 8.04 after I add/update the crontab? Thanks a bunch for your ...
RayJamesFun's user avatar
57 votes
2 answers
94k views

Ubuntu Server message says packages can be updated, but apt-get does not update any [duplicate]

Possible Duplicate: updates in amazon-ec2 ubuntu 10.04 server When I log into an Ubuntu 10.04.2 LTS server, I see the message: 42 packages can be updated. 18 updates are security updates. But ...
Mike T's user avatar
  • 751
55 votes
1 answer
113k views

what s+ S1+ T R+ mean in ps ax ps list

I run this command and got result this but not able to understand the result which node instance should i kill ps ax | grep node 23308 pts/3 S+ 0:00 sudo node index.js 23310 pts/3 Sl+ ...
Rahul Mehta's user avatar
  • 1,019
55 votes
7 answers
42k views

Headless Ubuntu server machine sometimes stuck at GRUB menu

I have Ubuntu 10.10 Server installed on a single-board machine in a semi-embedded environment; no keyboard or screen, just SSH access to it. So it's really frustrating when it occasionally boots up ...
mikepurvis's user avatar
  • 1,067
54 votes
4 answers
238k views

How to check cron logs in Ubuntu

I went to /var/log/cron but this file is empty. How to check if crontab is enabled or is running properly or not in ubuntu thanks
user avatar
54 votes
7 answers
122k views

How to get e-mail from (failed) cron-jobs in Ubuntu?

I create cron-jobs in Ubuntu by placing the executable in one of /etc/cron.{daily,hourly,monthly,weekly}. There are lots of directories starting with cron: kent@rat:~$ ls -ld /etc/cron* drwxr-xr-x 2 ...
Deleted's user avatar
  • 1,832
53 votes
3 answers
41k views

SSH connection lost during server upgrade - How to reconnect to process?

So, I was performing an Ubuntu Server upgrade from 11.04 to 11.10. I forgot about it in the background, and my SSH client timed out and disconnected (putty on Windows, go figure). The last thing on ...
Stephen Melrose's user avatar
53 votes
3 answers
123k views

Ubuntu ufw: set a rule on a per interface basis

I want to create a rule that allows anyone on eth1 to access port 80. Can UFW do this or should I go back to using Shorewall? To clarify: this is a capabilties question, can ufw handle interfaces as ...
Antonius Bloch's user avatar
53 votes
8 answers
114k views

Ubuntu Apache: httpd.conf or apache2.conf?

which one of these two files should I use to configure Apache? The httpd.conf is empty, while apache2.conf is not. It confuses me!
ajsie's user avatar
  • 1,255
52 votes
12 answers
66k views

Unzipping files that are flying in through a pipe

Can I make unzip or any similar programs work on the standard output? The situation is I'm downloading a zip file, which is supposed to be unzipped on the fly. Related issue: How do I pipe a ...
Alex's user avatar
  • 2,397
52 votes
5 answers
198k views

Failed tls handshake. Does not contain any IP SANs

I'm trying to set up logstash forwarder, but I have issues with making a proper secure channel. Trying to configure this with two ubuntu (server 14.04) machines running in virtualbox. They are 100% ...
connery's user avatar
  • 555
51 votes
2 answers
20k views

Prevent the possiblity of writing data to an unmounted mount point directory [duplicate]

I have an Ubuntu server where I'm automounting an external hard drive each boot. To do this, I've created an empty folder on the root partition, and the drive gets mounted "inside" this folder. ...
LonnieBest's user avatar
  • 1,530
50 votes
3 answers
120k views

How do I clear the "s" permission on a directory in Linux?

I have a directory that is showing up with the permission mask drwsrwsr-x. When I try to reset the permissions to 755 the S still remains. What is the "s" and why cant I change the permissions ...
Matt Elhotiby's user avatar
49 votes
4 answers
52k views

Can't get bower working - bower ESUDO Cannot be run with sudo

I get the following error when I run bower: bower ESUDO Cannot be run with sudo Thing is, I'm not running bower with sudo. The command I run is: bower install foo or bower search cats I am ...
Lothar_Grimpsenbacher's user avatar
49 votes
4 answers
129k views

How do I request a new IP address from my DHCP server using Ubuntu Server?

I know there is a simple command for this, but how do I tell my Ubuntu server instance to request a new IP address from the DHCP server on eth0?
Heat Miser's user avatar
48 votes
6 answers
52k views

How do you set a locale non-interactively on Debian/Ubuntu?

Usually, I run aptitude -y install locales then dpkg-reconfigure locales to set up locale. Now I want to put it into a shell script, how can I reliably do the following, automatically / non-...
kenn's user avatar
  • 695
47 votes
3 answers
101k views

How do I upgrade from PHP 5.3 to PHP 5.4.6 in Ubuntu?

Is there an easy way out to get the latest PHP? I have tried updating my package but none of it has 5.4.6 yet... if anyone knows on how to do it quickly, can it be shared here? I've tried compiling ...
user79356's user avatar
  • 627
47 votes
3 answers
74k views

UFW Firewall Rules ordering?

I have the following rules on our server within UFW: To Action From -- ------ ---- 22 ALLOW 217.22.12.111 22 ...
dannymcc's user avatar
  • 2,727
47 votes
6 answers
176k views

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 ...
GroovyPanda's user avatar
47 votes
7 answers
56k views

Why rsync is faster than NFS?

Few days ago I noticed something rather odd (at least for me). I ran rsync copying the same data and deleting it afterwards to NFS mount, called /nfs_mount/TEST. This /nfs_mount/TEST is hosted/...
grs's user avatar
  • 2,245
47 votes
1 answer
108k views

How do I tell what is running on which ports in Ubuntu?

How could I tell what is listening on which ports on Ubuntu? In other words, how do I get a list of ports that are in use?
Genadinik's user avatar
  • 1,143
46 votes
3 answers
359k views

How to check my PHP and MySQL version on Ubuntu VPS?

HI I am going to install MyBB but I am not sure whether I have installed the correct version of PHP and MySQL. PHP version 5.1.0 or above with XML Extension installed MySQL version 4.0 or ...
DocWiki's user avatar
  • 683
46 votes
5 answers
48k views

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?
Sandra's user avatar
  • 10.5k
46 votes
6 answers
103k views

Forwarding ports to guests in libvirt / KVM

How can I forward ports on a server running libvirt/KVM to specified ports on VM's, when using NAT? For example, the host has a public IP of 1.2.3.4. I want to forward port 80 to 10.0.0.1 and port 22 ...
steveh7's user avatar
  • 463
46 votes
6 answers
125k 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 ...
interstar's user avatar
  • 1,321
45 votes
4 answers
41k views

Ubuntu 15.10 Server; W: Possible missing firmware /lib/firmware/ast_dp501_fw.bin for module ast

I'm running Ubuntu 15.10 server on a Asrock E3C226D2I board. When I get a kernel update or run update-initramfs -u I get a warning about missing firmware: root@fileserver:~# update-initramfs -u ...
wouter's user avatar
  • 553
44 votes
2 answers
28k views

Damaged /vmlinuz and /initrd.img symbolic links after Kernel uninstall

OS: Ubuntu 8.04 LTS Server Edition We just rolled back an kernel update using the following command: sudo apt-get remove linux-image-2.6.24-24-server The uninstallation was successful, but it had ...
maxyfc's user avatar
  • 543
43 votes
3 answers
101k views

Linux: how to give a user permission to restart apache?

I have a script running under a non-root user which, under certain conditions, should restart apache httpd. What would be the simplest way for me to allow the user to do that? I'm using Ubuntu ...
itsadok's user avatar
  • 1,889
43 votes
6 answers
40k views

How do I permanently disable Linux's console screen saver, system-wide?

I've got an Ubuntu server that boots up in text mode. It rarely has a screen or keyboard attached to it, but when I do attach a screen, I usually have to attach a keyboard too, because the darn ...
raldi's user avatar
  • 987
43 votes
6 answers
57k views

How to disconnect from lxc-console

I'm working with lxc in Ubuntu 12.04, and it's really great. However, I am unable to disconnect from a lxc-console session after I've connected. I read somewhere that Ctrl-aq will disconnect me from ...
robbyt's user avatar
  • 1,662
42 votes
12 answers
37k views

Find last time update was performed with apt-get

I need to find the last time that the apt-get update command was run on my server. How can I determine this information?
Mark Roddy's user avatar
42 votes
4 answers
83k views

Setup ubuntu server to send mail()

I tried searching a lot but unable to find how to actually setup a ubuntu server, so that I can send mails through php using mail() function in php. I have apache2, mysql and php5 installed on my ...
Shishant's user avatar
  • 683
42 votes
6 answers
121k views

Improving TCP performance over a gigabit network with lots of connections and high traffic of small packets

I’m trying to improve my TCP throughput over a “gigabit network with lots of connections and high traffic of small packets”. My server OS is Ubuntu 11.10 Server 64bit. There are about 50.000 (and ...
Worker's user avatar
  • 647
41 votes
1 answer
102k views

Unable to execute gcc: No such file or directory

I am running Ubuntu LTS and I'm getting errors when trying to do some of my pip install stuff, like scrapy for example. This is the error I get: Unable to execute gcc: No such file or directory Error:...
J.Zil's user avatar
  • 1,123
41 votes
2 answers
33k views

Run command as Linux "system" user (shell = /bin/false)

I created a "system" user in Ubuntu 11.04 (adduser --system) for running certain cron jobs, but sometimes I want to test things out by manually running commands as that user. What's the easiest way to ...
EMP's user avatar
  • 5,162