systemd2init: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/systemd2init - from package: dh-systemd

You may install the required package with command apt-get install {package}
Error in other languages:
systemd2init: bevel nie gevind nie
systemd2init: comandă negăsită
systemd2init: comando não encontrado
systemd2init: commande introuvable
systemd2init: command not found
systemd2init: käsku ei ole
systemd2init: không tìm thấy lệnh
systemd2init: komanda nerasta
systemd2init: Kommando nicht gefunden.
systemd2init: kommandot finns inte
systemd2init: komut yok
systemd2init: nie znaleziono polecenia
systemd2init: níor aimsíodh an t-ordú
systemd2init: no se encontró la orden
systemd2init: no s'ha trobat l'ordre
systemd2init: opdracht niet gevonden
systemd2init: parancs nem található
systemd2init: perintah tidak ditemukan
systemd2init: príkaz nenájdený
systemd2init: příkaz nenalezen
systemd2init: команда не найдена
systemd2init: командата не е открита
systemd2init: 命令找不到
systemd2init: コマンドが見つかりません