First, DNS problems - Linode pointed me to https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/1674532 (mainly need to up sudo apt-get update && sudo apt-get upgrade, possibly reboot)
As quick fix, appended dns-nameservers 8.8.8.8 8.8.8.9
to /etc/network/interfaces and running "sudo service networking restart".
vi /etc/apt/sources.list Append:
deb http://repo.percona.com/apt xenial main testing
deb-src http://repo.percona.com/apt xenial main testing
Add Percona sig https://www.percona.com/blog/2016/10/13/new-signing-key-for-percona-debian-and-ubuntu-packages/ (apt-key adv --keyserver keys.gnupg.net --recv-keys 8507EFA5)
apt-get install percona-backup-24