ElFroggio
Firstly note that it will take many hours to backup to USB disk, depending on how much data is on your server, the speed of the USB connection & USB drive. Typically 4 hours for 350Gb or so. Similar for restore.
Method 1) Select backup to USB from the admin console, & on first boot of the new cleanly installed OS, it will ask if you want to restore from USB.
Insert the USB then & run the restore. How much easier than that.
Method 2) Use the standard backup to workstation option in server manager & select local USB disk.
Then install the new OS on the new hardware, do any basic configuration required for the network in order to get access, configure the backup job in server manager identically to how it was setup on the old server & then restore from the USB drive.
You do not need Affa & there is certainly nothing about Affa that is special regarding backup & restore. It may save some time at the actual moment of transfer, but it still takes time to do the full backup initially.
Make sure you include /opt or any other folders if you have stuff there you want to transfer.
See the Contrib wiki article "Backup with dar" for details about adding inclusions
Note with any of the supported backups, you will need to reinstall the contribs AFTER you have restored the backup data, as contrib rpms are not included in any backup.
See
http://wiki.contribs.org/Backup_server_config#Backup_and_Restore_concepts.2C_issues_and_other_informationRe Affa & USB.
Affa works with a USB drive OK, just configure the backup job to use a USB drive, as per Affa wiki Contrib article.
If you want or need more details re how to configure the affa job for USB, just ask again.