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

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