Stupid question regarding ZFS and `df -h` output

[Eric S Pulley]

On Sun, 10 Apr 2016 15:00:13 +0300
Aleksander Alekseev <afiskon at devzen.ru> wrote:

> Hello
> 
> I installed FreeBSD using steps like "Next -> Next -> ZFS -> use
> entire disk and don't bother me with stupid questions -> Next"
> 
> I have 128 Gb hard drive:
> 
> ada0 at ahcich0 bus 0 scbus0 target 0 lun 0
> ada0: <TOSHIBA THNSNS128GMCP TA4ABBF0> ATA8-ACS SATA 3.x device
> ada0: Serial Number 82GS10GGT2GY
> ada0: 600.000MB/s transfers (SATA 3.x, UDMA6, PIO 8192bytes)
> ada0: Command Queueing enabled
> ada0: 122104MB (250069680 512 byte sectors)
> 
> And here is `df -h` output:
> 
> Filesystem            Size    Used   Avail Capacity  Mounted on
> zroot/ROOT/default     95G     21G     74G    22%    /
> devfs                 1.0K    1.0K      0B   100%    /dev
> zroot/tmp              75G    153M     74G     0%    /tmp
> zroot/usr/home         89G     15G     74G    17%    /usr/home
> zroot/usr/ports        75G    859M     74G     1%    /usr/ports
> zroot/usr/src          76G    1.2G     74G     2%    /usr/src
> zroot/var/audit        74G     96K     74G     0%    /var/audit
> zroot/var/crash        75G    930M     74G     1%    /var/crash
> zroot/var/log          74G    360K     74G     0%    /var/log
> zroot/var/mail         74G    188K
> 74G     0%    /var/mail zroot/var/tmp          74G    136K
> 74G     0%    /var/tmp zroot                  74G     96K     74G
> 0%    /zroot
> 
> How exactly should I read this to get result "all 128 GB are used"?
> 

You have to change your way of thinking a little with ZFS. On my full
ZFS systems I usually make a shell alias for df to actually run `zfs
list -o mountpoint,quota,used,avail`. and I have quotas set on the
"traditional" mountpoints.

Mess around with the -o options to zfs list until it tells you want you
want to see.