Free space on ZFS is not reported correctly(?) [Resolved]

[namaedayo]

Thank you for reply.
I can't thank you enough!

Adam Nowacki wrote:
> By default zvols have refreservation property set to zvol size. You can
> set it to 'none' to make unused zvol disk space available to other datasets.


dedup is enabled for "zpool0/test-dedup" in experimental purposes.
I have knowledge of the risk of dedup. It has received the advice many
times in the kind people.
If ZFS to LZMA2 compression is implemented I'm glad.

kpneal wrote:
> Using dedup takes a surprisingly large amount of memory. Unless you only
have a small amount of data to dedup you probably shouldn't have dedup
turned on with only 32GB of memory.

[root at namaedayo-hp ~]# zfs get refreservation zpool0/namae-iSCSI
NAME                PROPERTY        VALUE      SOURCE
zpool0/namae-iSCSI  refreservation  82.5G      local

# zfs set refreservation=none zpool0/InnoDB
# zfs set refreservation=none zpool0/FreeBSD-10-1_i386-icc
# zfs set refreservation=none zpool0/FreeBSD-10-1_i386-icc_zfs
# zfs set refreservation=none zpool0/Ubuntu-14-04_server
# zfs set refreservation=none zpool0/Ubuntu_Desktop
# zfs set refreservation=none zpool0/namae-iSCSI
# zfs set refreservation=none zpool0/fedora-21-i686-LXDE
# zfs set refreservation=none zpool0/Ubuntu_Desktop

$ zfs list
NAME                                                USED  AVAIL  REFER
 MOUNTPOINT
zpool0                                             4.73T   580G   216K  /zpool0
zpool0/FreeBSD-Buckup                               169G   580G   169G
 /zpool0/FreeBSD-Buckup
zpool0/FreeBSD-Root                                 864G   580G   811G  /
zpool0/Ubuntu-14-04_server                         21.9G   580G  21.9G  -
zpool0/Ubuntu_Desktop                              7.18G   580G  7.18G  -
zpool0/Ubuntu_Desktop-i386                          135G   650G  48.9G  -
zpool0/freebsd-swap                                66.0G   630G  16.1G  -
zpool0/namae-iSCSI                                 59.3G   580G  59.3G  -
zpool0/namaedayo_work                               351G   580G   346G
 /zpool0/namaedayo_work
zpool0/test-dedup                                  53.8G   580G  53.8G
 /zpool0/test-dedup
zpool0/test-lz4                                    47.8G   580G  47.8G
 /zpool0/test-lz4

$ df -h
Filesystem                                           Size    Used
Avail Capacity  Mounted on
zpool0/FreeBSD-Root                                  1.4T    811G
580G    58%    /
devfs                                                1.0K    1.0K
0B   100%    /dev
linprocfs                                            4.0K    4.0K
0B   100%    /compat/linux/proc
linsysfs                                             4.0K    4.0K
0B   100%    /compat/linux/sys
fdescfs                                              1.0K    1.0K
0B   100%    /dev/fd
procfs                                               4.0K    4.0K
0B   100%    /proc