1 files changed, 14 insertions, 4 deletions

diff --git a/modules/zfssnap/zfssnap.py b/modules/zfssnap/zfssnap.py
index cb91564b..a05440a7 100644
--- a/modules/zfssnap/zfssnap.py
+++ b/modules/zfssnap/zfssnap.py
@@ -83,11 +83,21 @@ def prune(config, dry_run):
             keep.add(snap)
 
     within = config.gettimedelta('KEEP', 'within')
-    within_cutoff = _now() - within
+    if within > timedelta(seconds=0):
+        for base, snaps in items.items():
+            time_ref = max(snaps, key=lambda snap: snap['creation'], default=None)
+            if not time_ref:
+                logger.warn('Nothing to keep for ‘{base}’')
+                continue
 
-    for base, snap in [(base, snap) for base, snaps in items.items() for snap in snaps]:
-        if snap['creation'] >= within_cutoff:
-            keep_because(base, snap['name'], 'within')
+            logger.info('Using ‘{time_ref["name"]}’ as time reference for ‘{base}’')
+            within_cutoff = time_ref['creation'] - within
+
+            for snap in snaps:
+                if snap['creation'] >= within_cutoff:
+                    keep_because(base, snap['name'], 'within')
+    else:
+        logger.warn('Skipping rule ‘within’ since retention period is zero')
 
     prune_timezone = config.gettimezone('KEEP', 'timezone', fallback=tzlocal)