scsidev: 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:

/sbin/scsidev - from package: scsitools

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

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