Backtrack:  
Blog
 
showing posts tagged with 'ubuntu'
 
Mailman + ISPConfig: User unknown in virtual mailbox table
edited by on August 27th 2020, at 15:16

In a Mailman + ISPConfig type of setup, you may get the following error while sending an e-mail to the mailing list:

Error:
550 5.1.1 <leden@zweefvliegen-hasselt.be>: Recipient address rejected: User unknown in virtual mailbox table

When looking at the virtual aliases (in /var/lib/mailman/data/), the lists are empty.

You can resolve this by regenerating the aliases:

sudo /var/lib/mailman/bin/genaliases
sudo postmap /var/lib/mailman/data/transport-mailman
sudo postmap /var/lib/mailman/data/virtual-mailman

Afterwards, restart Postfix:

sudo service postfix restart
 
Enable auto-logon with systemd (non-GUI) (Ubuntu 16.04+ and Debian 8+)
edited by on March 21st 2019, at 12:24
The quickest way to enable auto-logon on Ubuntu 16.04+ and Debian (which are using systemd for management of their services) is by creating an override for the getty service, specifically for tty1 (or another tty if you prefer).

First, determine which tty you wish to have the auto-logon on. These are the terminals linked to the Alt+Fn keys, so tty1 = Alt+F1, tty2 = Alt+F2. The default is always tty1.

Next, create an override by typing:

sudo systemctl edit getty@tty1.service

This will open up a text editor where you can adjust the parameters like so:

[Service]ExecStart=ExecStart=-/sbin/agetty --noissue --autologin myusername %I $TERMType=idle

Replace myusername with the account you wish  ...
 
Configure tftpd-hpa to allow upload of new files
edited by on August 21st 2018, at 14:16
When installing tftpd-hpa, as a security measure, the service does not allow uploading new files. It does allow overwriting existing files, provided that the permissions are set correctly (as expected). The idea behind this is to secure TFTP a bit by only allowing uploads if the file already exists (and is writable). But this can be very tedious in some cases, where a lot of files have to be uploaded, and it is not possible to guess the names to create them in advance.

It is possible to configure tftpd-hpa to allow the creation of new files by adding the -c or --create parameter when starting the daemon.

For Ubuntu and Debian, this means editing the file /etc/default/tftpd-hpa, and adding   ...
 
Package repositories for old/obsolete Ubuntu releases
edited by on August 22nd 2017, at 15:09

Older, obsolete releases of Ubuntu are no longer available on localized mirrors. Instead, you must use the old-releases repositories. This is done by replacing the repository entries in /etc/apt/sources.list:

  • country.archive.ubuntu.com → old-releases.ubuntu.com
  • security.ubuntu.com → old-releases.ubuntu.com

For example:

us.archive.ubuntu.com/ubuntu/dists/natty/main/source/Sources

would become

old-releases.ubuntu.com/ubuntu/dists/natty/main/source/Sources

 
Shorewall not automatically starting on Debian 9 (and some versions on Ubuntu 16.04)
edited by on August 18th 2017, at 14:27
There's an issue with the Shorewall package in Debian 9 Stretch, causing Shorewall not to automatically start even when the required configuration files are in-place and/or modified. As stated here, the problem also exists on Ubuntu with some versions of the package (see article).

The problem lies with the package not enabling the startup script in systemd during installation. The solution is to manually enable this by running the following command (as sudo):

systemctl enable shorewall.service

This will enable Shorewall to automatically start during a reboot. Note that you will still have to set the correct parameters in /etc/default/shorewall (and possibly /etc/shorewall/shorewall.conf t  ...
 
Key server time out when trying to add a GPG public key
edited by on September 19th 2016, at 11:59
If you get a keyserver time out when trying to download a public key from a public GPG server, you may need to check your firewall settings. When receiving a public key, gpg connects to TCP port 11371, which not commonly opened up when you are behind a strict firewall. Luckily, most key servers also listen on port 80, allowing to get the public keys through that port.

When attempting to download a key and you are not able to connect to the default port, you will get something like:

gpg --keyserver keyserver.ubuntu.com --recv-keys 94558F59gpg: requesting key 94558F59 from hkp server keyserver.ubuntu.comgpg: keyserver timed outgpg: keyserver receive failed: keyserver error

To force gpg to d  ...
 
Completely disable automatic suspend in Ubuntu 14.04
edited by on August 12th 2015, at 12:00

To disable automatic suspend, but leave manual suspend working in Ubuntu 14.04, create the text file:

/etc/polkit-1/localauthority/50-local.d/com.ubuntu.disable-suspend.pkla

with contents:

[Disable suspend (upower)]
Identity=unix-user:*
Action=org.freedesktop.upower.suspend
ResultActive=no
ResultInactive=no
ResultAny=no

[Disable suspend (logind)]
Identity=unix-user:*
Action=org.freedesktop.login1.suspend
ResultActive=yes
ResultInactive=no
ResultAny=yes

[Disable suspend when others are logged in (logind)]
Identity=unix-user:*
Action=org.freedesktop.login1.suspend-multiple-sessions
ResultActive=yes
ResultInactive=no
ResultAny=yes
 
Change the console fonts on Ubuntu/Debian
edited by on June 12th 2015, at 15:55

You can efficiently change the console fonts, character sets and keymaps through the following command:

sudo dpkg-reconfigure console-setup

The configuration is stored in the file /etc/default/console-setup, and can be edited by hand as well.

The changes are effective for all virtual consoles after reboot. To apply the change for the current console, run:

setupcon

To prevent changing the console font completely (i.e. native system/BIOS font will be used), set the font to "do not change".
The equivalent in the config file is: 

FONTFACE=""
FONTSIZE=""
 
15 Things to Do After Installing Ubuntu 15.04 Desktop
edited by on June 9th 2015, at 16:18

Nice article about things you can do after a fresh install of Ubuntu on your computer:

http://www.tecmint.com/things-to-do-after-installing-ubuntu-15-04-desktop/

Very useful if you don't have a whole lot of experience with linux in general, and Ubuntu in particular.

 
VMware Server Console on Ubuntu 6.10 Edgy
edited by on March 28th 2007, at 11:10

If VMware Server Console doesn't work on your Ubuntu 6.10 Edgy install, here's what to do.

If after installing, the console does not launch, but instead takes up 100% CPU until the end of days (or until you kill it), try starting the console with this command:

LD_PRELOAD=/usr/lib/libdbus-1.so.3:$LD_PRELOAD vmware-server-console

This fixes some yet to be resolved issue around shared libs.

 
 
showing posts tagged with 'ubuntu'
 
 
« ‹December 2024› »
SunMonTueWedThuFriSat
1234567
891011121314
15161718192021
22232425262728
293031    
 
Links
 
Quote
« You only find out who is swimming naked when the tide goes out. »
Warren Buffett