qsgrep: 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/qsgrep - from package: libapache2-mod-qos

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

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