rmdtopvf: 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 CentOS possible default full paths are:

/usr/bin/rmdtopvf - from package: mgetty-voice

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

On Debian possible default full paths are:

/usr/bin/rmdtopvf - from package: mgetty-pvftools

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

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