--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/files/zfs_metrics/zfs.mtail	Wed Dec 07 23:02:57 2022 -0800
@@ -0,0 +1,16 @@
+gauge zfs_space_avail           by name
+gauge zfs_space_used            by name
+gauge zfs_space_used_snap       by name
+gauge zfs_space_used_ds         by name
+gauge zfs_space_used_ref_reserv by name
+gauge zfs_space_used_child      by name
+
+# output of `zfs list -Hp -o space`
+/(?P<name>\S+)\s+(?P<f0>\d+)\s+(?P<f1>\d+)\s+(?P<f2>\d+)\s+(?P<f3>\d+)\s+(?P<f4>\d+)\s+(?P<f5>\d+)/ {
+    zfs_space_avail[$name] = $f0
+    zfs_space_used[$name] = $f1
+    zfs_space_used_snap[$name] = $f2
+    zfs_space_used_ds[$name] = $f3
+    zfs_space_used_ref_reserv[$name] = $f4
+    zfs_space_used_child[$name] = $f5
+}