zktreeutil: command not found

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/zktreeutil - from package: zookeeper-bin

You may install the required package with command apt-get install {package}

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