setquota: 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/setquota - from package: quota

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

On Debian possible default full paths are:

/usr/sbin/setquota - from package: quota

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

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