Hopefully you have already been doing backups as your normal backup policy.
To make good backups of a QC installation:
1) get DB backups on the PROJECT level -- i.e. each QC project has a coresponding DB/schema in your DB back-end
2) get DB backup of qcsiteadmin_db (or similar name) DB/schema as it contains the overhead/management/admin data.
3) backup the entire project ''repository'' (by default: C:ProgramDataHPALMrepository) - each project indicates its project repository folder on the Project Details tab, ''Physical Directory'', and each domain will report the ''parent'' folder as well. Backup the part of the path up to the ''repository'' folder and get all child folders and contents - this will get ALL domains and ALL project repositories. If you believe the project repository locations are split into different ''parent'' repository folders (e.g. some project repository folders on C: and some one D:), try to combine them all under the same ''repository'' folder on the new target server.
4) if currently on QC11.50 or later, you also need get DB backup of default_lab_project_db (or similar name) DB/schema as it may contain data related to server-side test automations.
The DB's will be fairly easy to backup and migrate to the NEW DB instance, but the REPOSITORY may take some time (many hours) if you have large projects -- careful not to try to copy too large of a ''chunk'', you may need to do one domain or a few projects at a time, but not ALL at once.
We recommend using a freeware tool called Teracopy (or similar) as it can do CRC checks to verify the copy is complete. Windows often misses files when copying so many and taking up so much space.
Another way to backup the repository would be with an enterprise backup tool that can be directed to do entire drives or to get everything in certain folders. These backup tools can backup open files and are reliable to get verified good copies, and cal be directed to ''restore'' to a different server and drive.