zfs

is best.

See useful things

zfs list -o name,used,avail,refer,mountpoint,compressratio,used,usedbysnapshots,usedbychildren,usedbydataset

Destroy dataset

Check:
Mounted?
zfs get mounted mainframe/iocage Snapshots?
zfs list -t snapshot mainframe/iocage Destroy:
zfs destroy -r mainframe/iocage

Expand ZPOOL

for i in /sys/class/scsi_device/*/device/rescan; do echo "- - -" > $i; done Scan current SCSI devices for changes
parted /dev/sdb rm 9 8MB partition at the end of the disk may be deleted (perhaps an artefact from the Solaris days?)
growpart /dev/sdb 1 Increase ZFS partition to maximum size
zpool online -e ZPOOLNAME /dev/sdb Expand the pool