PB montage HDD NTFS CentOS

Bonjour ,
Je cherche a monter un HDD NTFS sous Linux CentOS 6.3_64 Bits j'ai installé le package NTFS-3G Mais quand j'essai de monter mon HDD je reçois comme message !!!


[root@oracle hdd]# mount -t ntfs /dev/sdb1 /mnt/hdd/
Mount is denied because the NTFS volume is already exclusively opened.
The volume may be already mounted, or another software may use it which
could be identified for example by the help of the 'fuser' command


Merci d'avance