When a site has outgrown its web host on all counts or when a web host does not keep its promises, moving web hosts becomes imperative. If a web host fails to provide much needed expansion requirements or technical support you need to upgrade to one that can meet your growth needs.
The first step is to ensure that you have all legal documents and contracts with you. Then make sure you have accurate and updated copies of all content, databases, scripts, and clientele lists. A back up needs to be done as a matter of routine not just when you need to move. Trouble can rear it head in the form of hardware failure or unexplained data losses.
Research the market thoroughly before deciding on a new hosting service. List your requirements and look for a host that can exceed your needs. It is not just bandwidth that you need to look at. Consider technical support, upgrading options, as well as whether the host is keeping up with new developments in the field.
It is important to run from the two web hosts simultaneously for a period until all debugging is carried out and problems are solved. Activate your new solution and upload all your pages, databases, and...