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 is specifically dedicated to Ubuntu questions.

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21 votes
5 answers

`sudo echo "bla" >> /etc/sysctl.conf` permission denied

Disclaimer: I'm pretty novice at sysadmin stuff. I'm trying to set up port forwarding in an AWS EC2 instance, this has to be done in the command-line because I don't want to go in and edit anything, ...
bevacqua's user avatar
  • 327
27 votes
8 answers

Accidently ran "chown www-data:www-data / -R" as root

I just ran this a few seconds ago. I managed to do Ctrl - C as soon as I realized what I started doing. So far the only directory it's started going through is /bin. I'm afraid to do anything else. ...
Will's user avatar
  • 441
42 votes
2 answers

How to reduce number of sockets in TIME_WAIT?

Ubuntu Server 10.04.1 x86 I've got a machine with a FCGI HTTP service behind nginx, that serves a lot of small HTTP requests to a lot of different clients. (About 230 requests per second in the peak ...
Alexander Gladysh's user avatar
6 votes
5 answers

What's needed for a complete backup system?

For my new server, I want to setup a proper backup solution. I've found a great setup that will do twice-daily incremental backups via Dropbox. I plan on backing up my various databases, the webroot ...
Brandon - Free Palestine's user avatar
74 votes
2 answers

How should an IT department choose a standard Linux distribution?

There is a lot of community feeling about what Linux distributions are appropriate for production server environments and which aren't, however, a lot of this feeling seems religiously based, and ...
wfaulk's user avatar
  • 6,958
204 votes
3 answers

How do I ask apt-get to skip any interactive post-install configuration steps?

I have a server build script which uses apt-get to install packages. It then puts pre-written configuration files directly in place, so the interactive post-install configuration dialog in packages ...
jl6's user avatar
  • 2,635
26 votes
2 answers

Weird syslog order

Have you ever seen wrong order in /var/log/syslog ? I think that it causes only crontab. Jun 28 22:20:01 alex CRON[2327]: (root) CMD (something > /dev/null) Jun 28 22:21:01 alex CRON[2700]: (root) ...
Tomasz's user avatar
  • 371
11 votes
5 answers

Can't restart nginx, bind() failed (98: Address already in use)

I know this topic exists in various different forms, but I'm having trouble solving my problem. If I run service nginx restart, nginx fails with the following log: 2015/03/14 08:36:42 [emerg] 9400#0: ...
dallen's user avatar
  • 249
104 votes
17 answers

CentOS vs. Ubuntu [closed]

I had a web server that ran Ubuntu, but the hard drive failed recently and everything was erased. I decided to try CentOS on the machine instead of Ubuntu, since it's based on Red Hat. That ...
DLH's user avatar
  • 1,115
88 votes
8 answers

Heartbleed: how to reliably and portably check the OpenSSL version?

I was looking at a reliable and portable way to check the OpenSSL version on GNU/Linux and other systems, so users can easily discover if they should upgrade their SSL because of the Heartbleed bug. ...
Martijn's user avatar
  • 833
82 votes
8 answers

Apache2 config variable is not defined

I installed apache2 on ubuntu 13.10. If I try to restart it using sudo /etc/init.d/apache2 restart I get this message: AH00558: apache2: Could not reliably determine the server's fully qualified ...
Kurt Bourbaki's user avatar
46 votes
6 answers

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 I want to forward port 80 to and port 22 ...
steveh7's user avatar
  • 463
24 votes
6 answers

Prevent SSH connection lost after logging into VPN on server machine

I encountered an issue that I can't deal with. When I'm logged onto an VPS over SSH and try to estabilish VPN connection on that VPS, the SSH connection between VPS and my machine get lost. I assume ...
mic22's user avatar
  • 341
18 votes
3 answers

How can I install packages without starting their associated services?

As you're probably aware, by default when you install a package on a Debian or Ubuntu based system, if the package contains a service, that service will generally be enabled and started automatically ...
Michael Hampton's user avatar
11 votes
8 answers

Ubuntu: Resize the root LVM(2?) partition

I have an Ubuntu virtual machine running in VirtualBox 2.2.4, and I created it on an 8gb virtual disk which is too small. So, I am trying to increase the size of the disk. So far, I have done this: ...
waterlooalex's user avatar
5 votes
1 answer

How do I set permissions structure for multiple users editing multiple sites in /var/www on Ubuntu 9.10?

I'm setting up an Ubuntu server that will have 3 or 4 VirtualHosts that I want users to be able to work in (add new files, edit old files, etc.). I currently plan on storing the sites in /var/www but ...
Michael T. Smith's user avatar
114 votes
12 answers

How to start/stop iptables on Ubuntu?

How can I start/stop the iptables service on Ubuntu? I have tried service iptables stop but it is giving "unrecognized service". Why is it doing so? Is there any other method?
user avatar
93 votes
5 answers

Why don't EC2 ubuntu images have swap?

I started a couple servers on EC2 and they don't have swap. Am I doing something wrong or is it that the machines just don't have any?
rafamvc's user avatar
  • 1,129
90 votes
9 answers

Command line program to test DHCP service

Is there a simple ping-like command to test whether a DHCP service is running on a network? ...on Linux
pufferfish's user avatar
  • 2,900
51 votes
2 answers

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
42 votes
4 answers

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
26 votes
4 answers

Linux e1000e (Intel networking driver) problems galore, where do I start?

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 ...
Evan Carroll's user avatar
  • 2,432
22 votes
8 answers

How to configure a shortcut for an SSH connection through a SSH tunnel

My company production servers (FOO, BAR...) are located behind two gateway servers (A, B). In order to connect to server FOO, I have to open a ssh connection with server A or B with my username ...
Simone Carletti's user avatar
11 votes
11 answers

Which Distributed File System as a backend for Cloud Computing?

I have a basic cloud running on Ubuntu Server (9.04) and Eucalyptus. Walrus (Eucalyptus' API compatable S3 implementation) stores files by on the cloud controller. However each of the other 4 server ...
Jaunty's user avatar
  • 151
10 votes
1 answer

No space left on device -- but there is space

I'm running an Ubuntu 12.04.1 server in a VMware virtualized environment that has a strange issue. Twice now, at seemingly random times, the machine has suddenly been unable to write to the root ...
Moduspwnens's user avatar
10 votes
2 answers

SSL site not using the correct IP in Apache and Ubuntu

I'm trying to set up an apache-ubuntu-php webserver. My webserver will host multiple SSL sites, each SSL site will have it's own IP address (unless there's a better way to do this). So I suppose the ...
learningtech's user avatar
  • 7,487
8 votes
2 answers

MySQL: Allow both remote AND local connections

In my Ubuntu's /etc/mysql/my.conf, I have: bind-address = # My external IP It works fine from remote, but when I want to connect locally, the app that uses on MySQL says:
Nicolas Raoul's user avatar
2 votes
1 answer

Dealing with multiple private DNS servers

I'll try to explain this as best I can... I'm on ubuntu 13.04, and I am running a local BIND instance at for access to basic wild-card DNS for development (i.e. "*.dev ==" - yes, ...
samlev's user avatar
  • 147
2 votes
1 answer

Installing Ubuntu 12.04 on HP Proliant DL380e with 1TB SAS Drive

I have an HP Proliant DL380e with a 1TB SAS Drive and I am trying to install ubuntu server 12.04 on it. I have created a RAID array using Array Controller Utility and had a RAID0 logical volume ...
jgtumusiime's user avatar
54 votes
3 answers

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
47 votes
3 answers

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
38 votes
2 answers

Can someone clarify Ubuntu (Debian) dist-upgrade for me?

I've got an Ubuntu 8.04 LTS server. There are several packages which are "kept back" ("the following updates have been kept back") when I do an apt-get upgrade. It's my understanding that I can do ...
Boden's user avatar
  • 5,008
33 votes
3 answers

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
Anonymous12345's user avatar
27 votes
9 answers

Ubuntu, how to setup a new machine like an existing one

I have one machine setup with the apps I need, and I'd like to install the same on a new Ubuntu box. Is there a script that will list all the installed apps, so that I can diff between the boxes and ...
Chris Kimpton's user avatar
26 votes
6 answers

How to reduce AWS EBS root volume size?

Enlarging an EC2 instance is easy like a breath (for instance, create an AMI, launch an instance from it and then change the storage size). But reducing it becomes more difficult. I’d like to reduce ...
herve's user avatar
  • 360
23 votes
4 answers

upstart scripts: run a task after networking goes up

I'm working on moving my current server setup to newer hardware, and migrating from ubuntu karmic koala to lucid lynx. Currently i'm using gw6c (compiled from the gogo6 website, as opposed to the ...
Journeyman Geek's user avatar
23 votes
5 answers

Scripted install of MySQL on Ubuntu

I need to write a script that will build my server from a fresh Ubuntu server install. Among things like Apache and PHP it needs to install MySQL. The only problem here is that when I install MySQL ...
Luke's user avatar
  • 3,856
15 votes
1 answer

Why did rebooting cause one side of my ZFS mirror to become UNAVAIL?

I just recently migrated a bulk data storage pool (ZFS On Linux 0.6.2, Debian Wheezy) from a single-device vdev configuration to a two-way mirror vdev configuration. The previous pool configuration ...
user's user avatar
  • 4,455
8 votes
2 answers

My cron tasks report command not found [duplicate]

This is the contents of my crontab file: 0 0,6,12,18 * * * cd /var/www/app/current && backup perform --trigger db_backup --config_file config/backup.rb --data-path db --log-path log --tmp-...
DEfusion's user avatar
  • 287
6 votes
7 answers

What causes PHP pages to consistently download instead of running normally

I'm running a Ubuntu Server on a VM, to test out different web forum solutions. I have set up a ~/public_html/ to be accessible with the apache2 web server, and that works fine. However when I go to ...
Jon Cox's user avatar
  • 165
5 votes
1 answer

Encrypted LVM on RAID1 - Failure testing, manual mount

We have an Ubuntu 10.04 LTS server set up with LVM running on top of disk encryption, which runs on top of a RAID1 volume comprised of two physical SATA disks. The configuration looks like this: ...
nedm's user avatar
  • 5,660
3 votes
5 answers

Enable access without "www." on Ubuntu

I want to enable the access to my site without the "www." prefix. I tried to insert this in my /etc/apache2/sites-available file: <VirtualHost *:80> serverName ...
Thiago Belem's user avatar
1 vote
1 answer

Postfix forwards to Gmail being rate limited even with unmodified headers

I've installed Postfix on Ubuntu 14.04 with the defaults. I then configured some virtual aliases to forward email from a few addresses to various personal (mostly Gmail) accounts. This is just to make ...
David Rahrer's user avatar
202 votes
14 answers

How to view all ssl certificates in a bundle?

I have a certificate bundle .crt file. doing openssl x509 -in bundle.crt -text -noout only shows the root certificate. how do i see all the other certificates?
pdeva's user avatar
  • 2,517
139 votes
13 answers

How do I get apt-get to ignore some dependencies?

How do I make apt-get ignore some dependencies? For example, I wanted to install mailx so I can use it to send email from cron scripts/report-generating tools. However, installing mailx also installs ...
FrancisV's user avatar
  • 1,786
109 votes
13 answers

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 ...
Chris's user avatar
  • 1,091
82 votes
5 answers

Best location to keep SSL certificates and private keys on Ubuntu servers?

On Ubuntu, it looks like the best place for a private key used to sign a certificate (for use by nginx) is in /etc/ssl/private/ This answer adds that the certificate should go in /etc/ssl/certs/ but ...
Adam Nelson's user avatar
  • 1,687
78 votes
9 answers

What is the debian-sys-maint MySQL user (and more)?

I have been bitten several times by the 'debian-sys-maint' user that is installed by default on the mysql-server packages installed from the Ubuntu repositories. Generally what happens is I pull a ...
Joe Holloway's user avatar
  • 1,929
63 votes
4 answers

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
37 votes
10 answers

Securing a fresh Ubuntu server [closed]

Say I've got a fresh install of Ubuntu, what steps should I take to secure it for use as a Rails application server?

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