Detailed documentation is available in the Downloads page
Documentation / Demo videos are available in the Demo Videos page
Q: Can DNNBackup export a specific portal from one DNN instance to another DNN instance in another DB?
A: No. it's very complex. There are too many direct, indirect and unknown relationships between different components (inside and outside the database). Especially 3rd party extensions which might be saving settings (perhaps encrypted who knows how), saving data who knows where, etc.
On top of that, there is the problem about DNN core versions mismatch between different DNN instances, installed/missing extensions and/or installed but featuring different versions.
In summary, a nightmare, for sure featuring too many 'gone wrong' scenarios, and thus a support hell which we don't want to be part of.
Q: Is it possible to Backup and Restore only a one Portal?
A: See previous question.
Evotiva DNN Backup video tutorials at DNN Hero (5.3 release)
How to automate the backup of your DotNetNuke site to Amazon S3 - part 1/4 - Video #201
How to test and restore the backup of your DotNetNuke site - part 1/2 - Video #205
Evotiva DNNBackup was featured on DNN Creative Magazine. Issue 62 (5.2 release)
Video Tutorial (7 videos - 62 mins).