What would be the best approach for complete SharePoint 2013 servers rebuild ?
As a short answer: Building a fresh server from scratch!
#Some instructions to clone your server:
In source server/farm,
- Take a full backup from your current farm.
- Take a full backup of SharePoint content databases in case you want to use Database-Attach method.
- Backup all the deployed SharePoint solutions (WSP) in your farm if exist.
- Determine the SQL version.
- Determine the build number and the latest CU installed on your source farm be installed on your destination farm.
In destination server/farm,
- Install a fresh SharePoint environment
- Windows, SQL Server.
Install and Configure SharePoint Server 2013 with the same source Enterprise Edition.
Install the latest Cumulative Update that already installed in source farm.
Note: You should be aware of the destination farm build number must be higher than or equal to the build number of source farm.
- Install the corresponding language pack that already installed on your source farm.
- Create a Web Application and Site Collection.
- Provision the corresponding Application Services.
- Restore your backup as I mentioned at Sharepoint 2013 web application migration