convmv: 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/convmv - from package: convmv

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

On Debian possible default full paths are:

/usr/bin/convmv - from package: convmv

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

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