zfs no free space

olivier@nas:/home/olivier % zpool list storage
NAME      SIZE  ALLOC   FREE   FRAG  EXPANDSZ    CAP  DEDUP  HEALTH  ALTROOT
storage  9,06T  8,87T   198G    15%         -    97%  1.00x  ONLINE  -
olivier@nas:/home/olivier % zfs list storage
NAME      USED  AVAIL  REFER  MOUNTPOINT
storage  7,09T      0   404M  /storage
olivier@nas:/home/olivier % zfs get reservation storage
NAME     PROPERTY     VALUE   SOURCE
storage  reservation  none    default
olivier@nas:/home/olivier % zfs list -rt all storage
NAME                USED  AVAIL  REFER  MOUNTPOINT
storage            7,09T      0   404M  /storage
storage/audio       124G      0   124G  /storage/audio
storage/documents   240G      0   240G  /storage/documents
storage/downloads  13,0G      0  13,0G  /storage/downloads
storage/films      6,58T      0  6,58T  /storage/films
storage/photos      143G      0   143G  /storage/photos