dt2dv: 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/dt2dv - from package: texlive-dviutils

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

On Debian possible default full paths are:

/usr/bin/dt2dv - from package: texlive-binaries

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

Error in other languages:
dt2dv: bevel nie gevind nie
dt2dv: comandă negăsită
dt2dv: comando não encontrado
dt2dv: commande introuvable
dt2dv: command not found
dt2dv: käsku ei ole
dt2dv: không tìm thấy lệnh
dt2dv: komanda nerasta
dt2dv: Kommando nicht gefunden.
dt2dv: kommandot finns inte
dt2dv: komut yok
dt2dv: nie znaleziono polecenia
dt2dv: níor aimsíodh an t-ordú
dt2dv: no se encontró la orden
dt2dv: no s'ha trobat l'ordre
dt2dv: opdracht niet gevonden
dt2dv: parancs nem található
dt2dv: perintah tidak ditemukan
dt2dv: príkaz nenájdený
dt2dv: příkaz nenalezen
dt2dv: команда не найдена
dt2dv: командата не е открита
dt2dv: 命令找不到
dt2dv: コマンドが見つかりません