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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21 votes
5 answers
29k views

`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, ...
  • 327
27 votes
8 answers
7k views

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. ...
  • 441
41 votes
2 answers
80k views

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 ...
6 votes
5 answers
3k views

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 ...
74 votes
2 answers
7k views

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 ...
  • 6,838
26 votes
2 answers
6k views

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) ...
  • 371
11 votes
5 answers
57k views

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: ...
  • 249
193 votes
2 answers
155k views

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 ...
  • 2,525
104 votes
17 answers
169k views

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 ...
  • 1,115
88 votes
8 answers
46k views

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. ...
  • 833
45 votes
6 answers
92k 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 ...
  • 453
17 votes
2 answers
12k views

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 ...
5 votes
1 answer
4k views

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 ...
107 votes
12 answers
728k views

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
79 votes
8 answers
233k views

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 ...
79 votes
5 answers
143k views

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 ...
  • 1,607
76 votes
9 answers
212k views

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
  • 2,700
47 votes
2 answers
17k 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. ...
  • 1,470
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 ...
  • 683
25 votes
4 answers
72k views

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 ...
  • 2,255
23 votes
6 answers
25k views

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 ...
  • 331
22 votes
8 answers
13k views

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 ...
11 votes
11 answers
15k views

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 ...
  • 151
10 votes
2 answers
7k views

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 ...
  • 7,223
10 votes
1 answer
4k views

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 ...
10 votes
8 answers
28k views

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: ...
  • 221
8 votes
2 answers
31k views

MySQL: Allow both remote AND local connections

In my Ubuntu's /etc/mysql/my.conf, I have: bind-address = 192.168.2.20 # My external IP It works fine from remote, but when I want to connect locally, the app that uses on MySQL says: java.net....
2 votes
1 answer
10k views

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 ...
2 votes
1 answer
2k views

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 127.0.0.1 for access to basic wild-card DNS for development (i.e. "*.dev == 127.0.0.1" - yes, ...
  • 147
92 votes
5 answers
50k views

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?
  • 1,119
50 votes
3 answers
101k 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 ...
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 ...
  • 627
37 votes
2 answers
17k views

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 ...
  • 4,958
31 votes
3 answers
85k 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
27 votes
9 answers
5k views

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 ...
23 votes
4 answers
31k views

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 ...
23 votes
5 answers
19k views

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 ...
  • 3,766
23 votes
6 answers
41k views

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 ...
  • 330
14 votes
1 answer
3k views

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 ...
  • 4,277
8 votes
2 answers
6k views

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-...
  • 287
6 votes
7 answers
33k views

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 ...
  • 165
5 votes
1 answer
3k views

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: ...
  • 5,610
3 votes
5 answers
6k views

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 mydomain.gov.br ...
1 vote
1 answer
1k views

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 ...
189 votes
14 answers
213k views

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?
  • 2,387
133 votes
13 answers
277k views

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 ...
  • 1,726
98 votes
12 answers
251k 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 ...
  • 981
76 votes
9 answers
113k views

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 ...
  • 1,849
62 votes
4 answers
55k 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 ...
  • 722
37 votes
10 answers
15k views

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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