qsf: 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/qsf - from package: qsf

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

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