zfs cannot create snapshot, out of space

Solution 1:

You have a refreservation set on your zvol, which reserves disk space for that dataset or zvol without regard to snapshots or clones. In order to make a snapshot there must be enough unreserved space left in the dataset to accommodate its referenced space, in this case 1.50T. Since your refreservation is (most likely) 1.61T you basically cannot do much of anything as all the free space gets reserved for that zvol (which will never use it).

To fix the problem, get rid of the refreservation.

zfs set refreservation=none zstore02/dsk02

To avoid the problem in future, create zvols with the -s (sparse) flag, which will also thin provision them:

zfs create -s -V 1600G zstore02/dsk02

If a thick provisioned volume is desired instead, create the volume and then set refreservation=auto.

zfs set refreservation=auto zstore02/dsk02