auconvert: 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 CentOS possible default full paths are:

/usr/bin/auconvert - from package: nas

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/auconvert - from package: nas-bin

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