+
+# zfs pool and file system (existing) where to create block devices
+test -z "$EXTP_ZFS" && EXTP_ZFS=tmp500g/$EXTP_VG
+
+# show numbers without compression for volume sizes
+test -z "$EXTP_USED" && EXTP_USED=logicalused
+
+export VOL_NAME
+
+zfs_get() {
+zfs get $1 -o value -p -H $EXTP_ZFS/$VOL_NAME
+}