afs-up: 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/afs-up - from package: openafs-client

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

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