From 2134b66df934aeb616fbc79d23c68010c756f268 Mon Sep 17 00:00:00 2001
From: n <n@tourmentine.com>
Date: Sun, 14 Sep 2014 00:36:27 +0200
Subject: [PATCH] zfsync.sh: send incremental zfs snapshots to another server

---
 zfsync.sh | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100755 zfsync.sh

diff --git a/zfsync.sh b/zfsync.sh
new file mode 100755
index 0000000..7f11021
--- /dev/null
+++ b/zfsync.sh
@@ -0,0 +1,59 @@
+#!/bin/sh
+
+# zfsync: sync zfs pool(s) between two servers
+
+# in case of failure, unepexpected reboot while syncing, etc.:
+# - destroy all snapshots on both local & ${bro}
+# - for i in ftp web mail; do zfs send servers/$i/home@newsync | ssh ${bro} zfs receive -vFd servers ;done
+# - for i in ftp web mail; do zfs rename servers/$i/home@newsync servers/$i/home@prevsync ;done
+# - ssh ${bro} "for i in ftp web mail; do zfs rename servers/$i/home@newsync servers/$i/home@prevsync ;done"
+
+bro="small"
+pools="ftp mail web"
+
+SENDNSCA=/usr/local/sbin/send_nsca\ -H\ 192.168.3.3\ -d\ ';;'\ -c\ /usr/local/etc/nagios/send_nsca.cfg
+HOSTNAME=`/bin/hostname -f | /usr/bin/cut -d '.' -f 1,1`
+SERVICENAME=zfsync
+LOGFILE=/tmp/zfsync.log
+sync_success=1
+
+alert()
+{
+	echo "${HOSTNAME};;${SERVICENAME};;2;CRITICAL - ZFS Sync failed at `date`, please check ${LOGFILE} for complete report." | ${SENDNSCA} >/dev/null
+	exit $?
+}
+if [ $1 ]
+then
+if [ $1 = "init" ]
+then
+echo "`date`: ZFSync INIT starting."
+	echo "wiping previous syncs"
+	for snapshot in `zfs list -t snapshot -o name | grep -e prevsync -e newsync`; do zfs destroy $snapshot ; done
+	ssh -q ${bro} 'for snapshot in `zfs list -t snapshot -o name | grep -e prevsync -e newsync`; do zfs destroy $snapshot ; done'
+	echo "making full snapshots"
+	for jail in $pools; do zfs snapshot servers/$jail/home@newsync;done
+	echo "sending full snapshots"
+	for jail in $pools; do zfs send servers/$jail/home@newsync | ssh -q ${bro} 'zfs receive -vFd servers' ;done
+	echo "renaming them to use them as a base for diff snapshots"
+	for jail in $pools; do zfs rename servers/$jail/home@newsync servers/$jail/home@prevsync ;done
+	ssh -q ${bro} 'for jail in ftp mail web; do zfs rename servers/$jail/home@newsync servers/$jail/home@prevsync ;done'
+	exit $?
+fi
+fi
+
+echo "`date`: ZFSync starting."
+for pool in $pools
+do
+	dataset="servers/${pool}/home"
+	echo "making new snapshot for ${pool}"
+	zfs snapshot ${dataset}@newsync || alert
+	echo "sending snapshot"
+	zfs send -i prevsync ${dataset}@newsync | ssh -q ${bro} "zfs receive -vFd servers" || alert
+	echo "cleaning"
+	zfs destroy ${dataset}@prevsync || alert
+	zfs rename ${dataset}@newsync ${dataset}@prevsync || alert
+	ssh -q ${bro} "zfs destroy ${dataset}@prevsync && zfs rename ${dataset}@newsync ${dataset}@prevsync" || alert
+done
+
+echo
+echo "${HOSTNAME};;${SERVICENAME};;0;OK - ZFS Sync succeeded at `date`" | ${SENDNSCA} >/dev/null