hroller: 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/lib/ganeti/2.12/usr/bin/hroller - from package: ganeti-htools-2.12
/usr/bin/hroller - from package: ganeti-htools
/usr/bin/hroller - from package: ganeti

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