Installation du quota bloquée sur repquota

Je veux utiliser group-quota sur mon serveur Ubuntu 12.04 LTS.

J'ai commencé par les étapes suivantes :

$ apt-get install quota

Modifier /etc/fstab

proc /proc proc defaults 0 0
none /dev/pts devpts gid=5,mode=620 0 0
# /dev/hda1 during Installation (RescueSystem)
UUID=9f906035-68d3-4066-9d58-2b070298e175 none swap sw 0 0
# /dev/hda2 during Installation (RescueSystem)
UUID=467ed71a-2c16-4b17-9a25-2b2962cf2431 /boot ext3 defaults 0 0
# /dev/hda3 during Installation (RescueSystem)
UUID=1f06497c-cd88-6f4d-a10b-8d30b7646adb / ext4 defaults,grpquota 0 0

Redémarrer mon serveur.

$ quotacheck -avg
quotacheck: Cannot remount filesystem mounted on / read-only so counted values might not be right.
Please stop all programs writing to filesystem or use -m flag to force checking.

Alors j'essaie

$ quotacheck -avgm
quotacheck: Scanning /dev/disk/by-uuid/1f06497c-cd88-6f4d-a10b-8d30b7646adb [/] done
quotacheck: Old user file name could not been determined. Usage will not be    substracted.
quotacheck: Cannot stat old group quota file //aquota.group: No such file or directory.    Usage will not be substracted.
quotacheck: Checked 29572 directories and 309976 files
quotacheck: Old file not found.

Redémarrer le service de quotas

$ /etc/init.d/quota restart

Et maintenant je suis coincé ici

$ repquota / 
repquota: Not all specified mountpoints are using quota.

Où est mon erreur ?

Gracias