Debian

When upgrading to Gnome 3.16 you might find yourself in the situtation that your mouse pointer speed has changed. To revert this run the following command: /usr/bin/xset m default

When upgrading Apache to version 2.4 some of your config files need to be changed. Allow from all needs to be changed to Require all granted Otherwise your virtualhost config is not correct and Apache won’t work correctly.

When all mail clients are working fine with dovecot – Outlook won’t. The first thing you might want to check resides in the following file: /etc/dovecot/conf.d/10-auth.conf The default value for disable_plaintext_auth is “yes” – change it to “no”: disable_plaintext_auth = no

After upgrading to Debian 8.0 (jessie) Skype stopped working with the following error message: skype: error while loading shared libraries: libGL.so.1: cannot open shared object file: No such file or directory There is a really simple fix available: sudo ln -s /usr/lib/mesa-diverted/i386-linux-gnu/libGL.so.1 /usr/lib/i386-linux-gnu/ Done.

In most scenarios you won’t need Xdebug on your CLI. Also it is recommended to disable it if you use Composer . sudo php5dismod -s cli xdebug

If you want to destroy all data on a device use the following command. shred is part of the coreutils package. /usr/bin/shred -v -f /dev/sda Data destroyed by shred can’t be restored unless you invest a lot of time and use special equipment. Use with caution. The option -n can be used to increase the amount of iterations (default: 3).

If your system does not boot up und you’re dropped to an initramfs shell after “waiting for root filesystem” fails – check your mdadm config /etc/mdadm/mdadm.conf Make sure it contains the correct definitions which are available with mdadm --detail --scan Adjust your config and run update-initramfs -u -k all to make the system bootable again.

Once in a while it might happen to you that you attempt to boot some Debian machine and some fsck errors occur. Debian will then present you a maintenance shell and ask for your root password. There are two options at this point: Enter your root password or hit CTRL-D to continue. Continuing will not resolve the problem as the fsck error needs to be fixed manually. If you don’t know your root password or you’re just to lazy to type in a 30 character string the following might help. ...

In case an IP gets banned by fail2ban and you want to remove it: The following command gives you an overview of all chains and the banned IPs along with their corresponding number. iptables -L -n --line-numbers To unban an IP use this command with the correct chain and number: iptables -D fail2ban-ssh 2 Another method is the usage of fail2ban-client: fail2ban-client set sasl unbanip IP

Virtualmin/Webmin ships with a self-signed SSL certificate. In case you want to generate a new one, here’s how: openssl rsa -in webmin.key -out webmin.pem openssl req -new -key webmin.key -out webmin.csr openssl x509 -req -days 1095 -in webmin.csr -signkey webmin.key -out webmin.crt cat webmin.crt >> webmin.pem cd /etc/webmin/ cp miniserv.pem miniserv.pem.bak cp /root/ssl/webmin.pem miniserv.pem service webmin restart