About all the things, but mainly Drupal, Ubuntu, CentOS and hosting

To reset your MySQL root password in SSH, simply run the following sequence of commands:


/etc/init.d/mysqld stop
mysqld_safe --skip-grant-tables &
mysql -u root
use mysql;
update user set password=PASSWORD("newrootpassword") where User='root';
flush privileges;
quit
/etc/init.d/mysqld stop
/etc/init.d/mysqld start

On Fedora 7.x based systems, which come with MariaDB instead of MySQL, run:

<?php
systemctl stop mariadb
mysqld_safe --skip-grant-tables &
mysql -u root
use mysql;
update user set password=PASSWORD("newrootpassword") where User='root';

At times we often forget the webmin password for a given user, say root, or after repeated failed login attempts webmin locks the account and one cannot login anymore. In this case you need to wait for couple, three minutes and you will be able to try to login again. However, if you've forgotten your password and need to change it, then login to the server via ssh and run the following command:

For RHEL/CentOS:


/usr/libexec/webmin/changepass.pl /etc/webmin root NEWPASSWORD


For Debian/Ubuntu


/usr/share/webmin/changepass.pl /etc/webmin root NEWPASSWORD

You need EPEL repo to install php-mcrypt:


yum -y install http://mirror.us.leaseweb.net/epel/6/x86_64/epel-release-6-7.noarch.rpm
yum -y install php-mcrypt

Here is the code for installing EPEL repository on CentOS 6.4:

rpm -Uvh http://fedora.mirrors.pair.com/epel/6/x86_64/epel-release-6-8.noarch.rpm

How do you go about increasing KVM virtual machine guest's disk space from the command line if you initially set insufficient amount of disk space?

1. Shutdown the VM
2. Move the current image
   
mv mykvm.img mykvm.img.bak
3. Create a new image
   
qemu-img create -f raw addon.raw 30G
4. concatenate the 2 images
   
cat mykvm.img.bak addon.raw >> mykvm.img
5. start the VM (using the newly created mykvm.img)
6. run fdisk inside VM and delete & re-create LVM partition
   % fdisk /dev/vda
...