amcleanup: 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/sbin/amcleanup - from package: amanda-server

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

On Debian possible default full paths are:

/usr/sbin/amcleanup - from package: amanda-server

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

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