diff --git a/functions/backup_restore/zfs/cache.py b/functions/backup_restore/zfs/cache.py
index 0c5151e..7a14f28 100644
--- a/functions/backup_restore/zfs/cache.py
+++ b/functions/backup_restore/zfs/cache.py
@@ -72,10 +72,14 @@ def _load_snapshots(self) -> dict:
 
     def _convert_size_to_bytes(self, size_str):
         size_units = {"K": 1024, "M": 1024**2, "G": 1024**3, "T": 1024**4}
-        if size_str[-1] in size_units:
-            return int(float(size_str[:-1]) * size_units[size_str[-1]])
-        else:
-            return int(size_str)
+        try:
+            if size_str[-1] in size_units:
+                return int(float(size_str[:-1]) * size_units[size_str[-1]])
+            else:
+                return int(size_str)
+        except ValueError:
+            self.logger.error(f"Invalid size string: {size_str}")
+            return 0
 
     def hard_refresh(self):
         """
@@ -189,4 +193,4 @@ def remove_snapshot(self, snapshot: str):
         with self._lock:
             if snapshot in ZFSCache._snapshots:
                 del ZFSCache._snapshots[snapshot]
-                self.logger.debug(f"Removed snapshot: {snapshot}")
+                self.logger.debug(f"Removed snapshot: {snapshot}")
\ No newline at end of file
diff --git a/functions/backup_restore/zfs/snapshot.py b/functions/backup_restore/zfs/snapshot.py
index a9b9320..f8f354b 100644
--- a/functions/backup_restore/zfs/snapshot.py
+++ b/functions/backup_restore/zfs/snapshot.py
@@ -83,10 +83,14 @@ def get_snapshot_refer_size(self, snapshot: str) -> int:
     @type_check
     def _convert_size_to_bytes(self, size_str):
         size_units = {"K": 1024, "M": 1024**2, "G": 1024**3, "T": 1024**4}
-        if size_str[-1] in size_units:
-            return int(float(size_str[:-1]) * size_units[size_str[-1]])
-        else:
-            return int(size_str)
+        try:
+            if size_str[-1] in size_units:
+                return int(float(size_str[:-1]) * size_units[size_str[-1]])
+            else:
+                return int(size_str)
+        except ValueError:
+            self.logger.error(f"Invalid size string: {size_str}")
+            return 0
 
     @type_check
     def delete_snapshot(self, snapshot: str) -> dict: