From 44dc136c8a57dd70982cf725c9b2a5d2a083474a Mon Sep 17 00:00:00 2001
From: Jochen Welzel <jochen.welzel@de.clara.net>
Date: Thu, 7 Jan 2021 09:54:55 +0100
Subject: [PATCH] add old snapshot deletion

---
 libvirt-zsh-backup.sh | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/libvirt-zsh-backup.sh b/libvirt-zsh-backup.sh
index 4230444..799e822 100644
--- a/libvirt-zsh-backup.sh
+++ b/libvirt-zsh-backup.sh
@@ -35,6 +35,13 @@ DATE=$(date "+%Y%m%d%H%M")
 DATE30=$(date -d "-30day" "+%Y%m%d")
 SNAPNAME="backup_$DATE"
 
+abortFunction()
+{
+    zfs set backup:success="false" $SRCZFS
+    zfs set backup:failed="$DATE" $SRCZFS
+    exit 1
+}
+
 VMDISKS=$(virsh domblklist $VM | egrep -o vd.)
 DISKSPEC=""
 for disk in $VMDISKS
@@ -55,7 +62,7 @@ then
     if [ $? -ne 0 ]
     then
         echo "VM snapshot creation failed" >&2
-        exit 1
+        abortFunction
     else
 	echo "Snapshot created without --quiesce"
     fi
@@ -65,7 +72,7 @@ zfs snapshot "$SRCZFS"@"$SNAPNAME"
 if [ $? -ne 0 ]
 then
     echo "ZFS snapshot creation failed" >&2
-    exit 1
+    abortFunction
 fi
 
 for disk in $VMDISKS
@@ -79,7 +86,7 @@ do
     if [[ $disk == *"snapshot"* ]]
     then
 	echo "Snapshot deletion failed for $disk" >&2
-	exit 1
+	abortFunction
     fi
 done
 
@@ -102,9 +109,20 @@ then
     zfs set backup:date="$DATE" $SRCZFS
     zfs destroy "$SRCZFS"@"$LASTSNAP"
 else
-    zfs set backup:success="false" $SRCZFS
-    zfs set backup:failed="$DATE" $SRCZFS
+    abortFunction
 fi
 
-
 zfs destroy tank/snapshots/$VM
+
+# cleanup old backups
+
+OLDSNAPS=$(ssh $DESTHOST zfs list -r -t snapshot -o name $DESTZFS 2>/dev/null | grep $DATE30)
+if [ ${#OLDSNAPS} -gt 0 ]
+then
+    for oldsnap in $OLDSNAPS
+    do
+	ssh $DESTHOST sudo zfs destroy $oldsnap
+    done
+else
+    echo "No old snapshots to cleanup"
+fi