dv2dt: 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/dv2dt - from package: texlive-dviutils

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

On Debian possible default full paths are:

/usr/bin/dv2dt - from package: texlive-binaries

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

Error in other languages:
dv2dt: bevel nie gevind nie
dv2dt: comandă negăsită
dv2dt: comando não encontrado
dv2dt: commande introuvable
dv2dt: command not found
dv2dt: käsku ei ole
dv2dt: không tìm thấy lệnh
dv2dt: komanda nerasta
dv2dt: Kommando nicht gefunden.
dv2dt: kommandot finns inte
dv2dt: komut yok
dv2dt: nie znaleziono polecenia
dv2dt: níor aimsíodh an t-ordú
dv2dt: no se encontró la orden
dv2dt: no s'ha trobat l'ordre
dv2dt: opdracht niet gevonden
dv2dt: parancs nem található
dv2dt: perintah tidak ditemukan
dv2dt: príkaz nenájdený
dv2dt: příkaz nenalezen
dv2dt: команда не найдена
dv2dt: командата не е открита
dv2dt: 命令找不到
dv2dt: コマンドが見つかりません