ZFS mount dataset for zone

I shutdown my non-global zone and umount her point zfs zonepath. command for umount: zfs unmount -f zones-pool/one-zone details: zfs list | grep one zones-pool/one-zone 15,2G 9,82G 32K /zones-fs/one-zone zones-pool/one/rpool/ROOT/solaris 15,2G 9,82G 7,83G /zones-fs/one/root in the above, it is seen that there is an occupied space, 9.82G of 15.2G more details: # zfs get mountpoint zones-pool/one-zone NAME PROPERTY VALUE SOURCE zones-pool/one-zone mountpoint /zones-fs/one-zone local # zfs get mounted zones-pool/one-zone NAME PROPERTY VALUE SOURCE zones-pool/one-zone mounted no - but, if I try mount point zfs I can not see the content step 1 mount: zfs mount zones-pool/one-zone step 2 see mount with df -h: df -h | grep one zones-pool/one-zone/rpool/ROOT/solaris 25G 32K 9,8G 1% /zones-fs/one-zone/root zones-pool/one-zone 25G 32K 9,8G 1% /zones-fs/one-zone step 3 list content: ls -l /zones-fs/one-zone/root total 0 why? also in step 2, you see that df -h prints 1% used I do not understand