djvups: 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/djvups - from package: djvulibre

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

On Debian possible default full paths are:

/usr/bin/djvups - from package: djvulibre-bin

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

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