repquota: 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/repquota - from package: quota

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

On Debian possible default full paths are:

/usr/sbin/repquota - from package: quota

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

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