List the size of all the datasets

zfs list -o name,used

Create a zfs dataset

zfs create zpool1/datasetname

You can also create a blockdevice on zfs. Which is called a zvol Create a zvol with 100GB size

zfs create -V 100G [zfspl]/[dataset]

Create a encrypted dataset with a passhprase. It will prompt you for a passphrase

zfs create -o encryption=on -o keylocation=prompt -o keyformat=passphrase zpool1/dataset

Load the key to decrypt a ZFS dataset. This is needed after a reboot to access your data.

zfs load-key -r zpool1/dataset

Sort snapshots by date

zfs list -t snapshot -o name,creation -s creation