From ee03da2f9b44401fff02851780493b30abfb0b39 Mon Sep 17 00:00:00 2001
From: Edwin Eefting <edwin@datux.nl>
Date: Sun, 15 Mar 2020 22:54:14 +0100
Subject: [PATCH] exposed --min-change value as a parameter. (was hardcoded at
200000)
---
bin/zfs-autobackup | 56 +++++++++++++++++++++++++++++-----------------
1 file changed, 35 insertions(+), 21 deletions(-)
diff --git a/bin/zfs-autobackup b/bin/zfs-autobackup
index d80c991..aa88600 100755
--- a/bin/zfs-autobackup
+++ b/bin/zfs-autobackup
@@ -498,7 +498,6 @@ class ZfsDataset():
'volume': [ "canmount" ],
}
- ZFS_MAX_UNCHANGED_BYTES=200000
def __init__(self, zfs_node, name, force_exists=None):
"""name: full path of the zfs dataset
@@ -691,12 +690,14 @@ class ZfsDataset():
return(ret)
- def is_changed(self):
+ def is_changed(self, min_changed_bytes=1):
"""dataset is changed since ANY latest snapshot ?"""
self.debug("Checking if dataset is changed")
- #NOTE: filesystems can have a very small amount written without actual changes in some cases
- if int(self.properties['written'])<=self.ZFS_MAX_UNCHANGED_BYTES:
+ if min_changed_bytes==0:
+ return(True)
+
+ if int(self.properties['written'])<min_changed_bytes:
return(False)
else:
return(True)
@@ -820,24 +821,35 @@ class ZfsDataset():
@cached_property
- def is_changed_ours(self):
- """dataset is changed since OUR latest snapshot?"""
-
- self.debug("Checking if dataset is changed since our snapshot")
-
- if not self.our_snapshots:
- return(True)
+ def written_since_ours(self):
+ """get number of bytes written since our last snapshot"""
+ self.debug("Getting bytes written since our last snapshot")
latest_snapshot=self.our_snapshots[-1]
cmd=[ "zfs", "get","-H" ,"-ovalue", "-p", "written@"+str(latest_snapshot), self.name ]
+
output=self.zfs_node.run(readonly=True, tab_split=False, cmd=cmd, valid_exitcodes=[ 0 ])
+
+ return(int(output[0]))
+
+
+ def is_changed_ours(self, min_changed_bytes=1):
+ """dataset is changed since OUR latest snapshot?"""
+
+ if min_changed_bytes==0:
+ return(True)
+
+ if not self.our_snapshots:
+ return(True)
+
#NOTE: filesystems can have a very small amount written without actual changes in some cases
- if int(output[0])<=self.ZFS_MAX_UNCHANGED_BYTES:
+ if self.written_since_ours<min_changed_bytes:
return(False)
return(True)
+
@cached_property
def recursive_datasets(self, types="filesystem,volume"):
"""get all datasets recursively under us"""
@@ -1293,20 +1305,18 @@ class ZfsNode(ExecuteNode):
return(self.backup_name+"-"+time.strftime("%Y%m%d%H%M%S"))
- def consistent_snapshot(self, datasets, snapshot_name, allow_empty=True):
+ def consistent_snapshot(self, datasets, snapshot_name, min_changed_bytes):
"""create a consistent (atomic) snapshot of specified datasets, per pool.
- allow_empty: Allow empty snapshots. (compared to our latest snapshot)
"""
pools={}
#collect snapshots that we want to make, per pool
for dataset in datasets:
- if not allow_empty:
- if not dataset.is_changed_ours:
- dataset.verbose("No changes since {}".format(dataset.our_snapshots[-1].snapshot_name))
- continue
+ if not dataset.is_changed_ours(min_changed_bytes):
+ dataset.verbose("No changes since {}".format(dataset.our_snapshots[-1].snapshot_name))
+ continue
snapshot=ZfsDataset(dataset.zfs_node, dataset.name+"@"+snapshot_name)
@@ -1399,7 +1409,8 @@ class ZfsAutobackup:
parser.add_argument('--other-snapshots', action='store_true', help='Send over other snapshots as well, not just the ones created by this tool.')
parser.add_argument('--no-snapshot', action='store_true', help='Dont create new snapshots (usefull for finishing uncompleted backups, or cleanups)')
parser.add_argument('--no-send', action='store_true', help='Dont send snapshots (usefull for cleanups, or if you want a serperate send-cronjob)')
- parser.add_argument('--allow-empty', action='store_true', help='If nothing has changed, still create empty snapshots.')
+ parser.add_argument('--min-change', type=int, default=200000, help='Number of bytes written after which we consider a dataset changed (default %(default)s)')
+ parser.add_argument('--allow-empty', action='store_true', help='If nothing has changed, still create empty snapshots. (same as --min-change=0)')
parser.add_argument('--ignore-replicated', action='store_true', help='Ignore datasets that seem to be replicated some other way. (No changes since lastest snapshot. Usefull for proxmox HA replication)')
parser.add_argument('--no-holds', action='store_true', help='Dont lock snapshots on the source. (Usefull to allow proxmox HA replication to switches nodes)')
#not sure if this ever was usefull:
@@ -1437,6 +1448,9 @@ class ZfsAutobackup:
if self.args.test:
self.args.verbose=True
+ if args.allow_empty:
+ args.min_change=0
+
self.log=Log(show_debug=self.args.debug, show_verbose=self.args.verbose)
@@ -1488,7 +1502,7 @@ class ZfsAutobackup:
else:
self.set_title("Filtering already replicated filesystems")
for selected_source_dataset in selected_source_datasets:
- if selected_source_dataset.is_changed():
+ if selected_source_dataset.is_changed(self.args.min_change):
source_datasets.append(selected_source_dataset)
else:
selected_source_dataset.verbose("Ignoring, already replicated")
@@ -1496,7 +1510,7 @@ class ZfsAutobackup:
if not self.args.no_snapshot:
self.set_title("Snapshotting")
- source_node.consistent_snapshot(source_datasets, source_node.new_snapshotname(), allow_empty=self.args.allow_empty)
+ source_node.consistent_snapshot(source_datasets, source_node.new_snapshotname(), min_changed_bytes=self.args.min_change)