This is because the sysstat package does not actually have a systemd unit. It just has a sysvinit init.d script, so you can't enable/disable this via systemd. You need to enable/disable it via update-rc.d (or manual symlinks in /etc/rc?.d/).
** Changed in: systemd (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1447807 Title: systemctl enable fails to enable a SysV service To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1447807/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs