dmraid-activate: 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/dmraid-activate - from package: dmraid

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

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