quotaoff: 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:

/sbin/quotaoff - from package: quota

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

On Debian possible default full paths are:

/sbin/quotaoff - from package: quota

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

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