How to upgrade from Fedora 20 to 21

At the moment all I can think of is this

Don’t know of any official way to do it but could be wrong

Thanks for the link , I follow the instruction in https://www.digitalocean.com/community/questions/how-to-unofficially-upgrade-to-fedora-21

After do it, i had some problems

i could not restart , or shutdown the server, when i tried to reboot the server i got this message

“Failed to start reboot.target: Activation of org.freedesktop.systemd1 timed out Failed to open /dev/initctl: No such device or address Failed to talk to init daemon”

and when i tried to start any service i got the next message “Failed to start fail2ban.service: Activation of org.freedesktop.systemd1 timed out” (this example is with fail2ban service in each service the name of the service change)

or when i tried to see the status i got … “Failed to get properties: Activation of org.freedesktop.systemd1 timed out”

I had to choose another kernel “Fedora 21 x64 vmlinuz-3.17.8-300.fc21.x86_64” , applied all the updates , i restarted the server from the web panel

and installed again fail2ban because the module relate with Firewalld was erased with the updates

and now all is working ok.

Thanks