discid: 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 Debian possible default full paths are:

/usr/bin/discid - from package: flactag

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

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