How to reset linux root password with SystemRescueCD?

Sometimes we forget root password and needs to reset. One of the approach is to reset via SystemRescueCD.

How to reclaim free space/shrink qcow2 file?

Qcow2 file grows overtime; even if we delete files and snapshots. It still does not reduce the file size. The only way to that is to fill the disk with zero and then convert the disk to qcow2.

How to shrink qcow2 file (LVM Logical Volume Manager, XFS file system)?

First we need to shrink the partition, and then shrink the qcow2 file.

How to add additional hard drive (disk image) to KVM virtual machine?

This section covers adding storage devices to a guest. Additional storage can only be added as needed.

How To Use HAProxy to Set Up MySQL Load Balancing?

Doing MySQL load balancing on HAProxy has several advantages; such as ip address restriction. Configuring MySQL to use HAProxy proxy protocol is a ticky part. It needs to know HAProxy ip address.