zfSync: synchronizes snapshots between two systems

funcs

@@ -0,0 +1,37 @@
+#!/bin/sh -
+
+. /etc/rc.subr
+
+# checknumber var
+#	Test $1 variable, and warn if not set to unsigned number.
+#	Return 0 if it's not a number, nonzero otherwise.
+
+checknumber() {
+	eval _value=\$${1}
+	debug "checknumber: $1 is set to $_value."
+
+	case $_value in
+	*[!0-9]*)
+		warn "$1 is not set properly."
+		return 0
+		;;
+	*)
+		return 1
+	esac
+}
+
+# checknotempty var
+#	Test $1 variable and warn if it doesn't contain anything.
+#	Return 0 if it has no data, nonzero otherwise.
+
+checknotempty() {
+	eval _value=\$${1}
+	debug "checknotempty: $1 is set to $_value."
+
+	if [ -z "$_value" ]; then
+		warn "$1 is not set properly."
+		return 0
+	else
+		return 1
+	fi
+}

xPERIODICx_zfSync.sh

@@ -0,0 +1,137 @@
+#!/bin/sh -
+
+: ${daily_synczfs_enable="NO"}
+: ${daily_synczfs_root=""}
+: ${daily_synczfs_user="backup"}
+
+# daily_synczfs_servers:
+#		space separated list of server names (resolvable)
+#
+# daily_synczfs_<server>_input_filter:
+#		all data on remote system would be piped through this command[s]
+#		possible usage:
+#		 - compression: '| xz -9e' or '| bzip2 -9';
+#		 - rate limiting: '| mbuffer -r 256k' or '| pv -L 256k', notice that misc/mbuffer or sysutils/pv should be installed.
+#
+# daily_synczfs_<server>_output_filter:
+#		all data on local system would be piped through this command[s]
+#		possible usage:
+#		 - decompression: '| xz -d' or '| bzip2 -d'.
+#
+# daily_synczfs_<server>_fs:
+#		space separated list of remote filesystem aliases
+#
+# daily_synczfs_<server>_hostname:
+#		full host name of remote system, if not present substituted by <server>
+#
+# daily_synczfs_<server>_<alias>_rfsname:
+#		full zfs filesystem name on remote system
+#
+# daily_synczfs_<server>_<alias>_fsname:
+#		last part of zfs filesystem name on local system (resides in daily_synczfs_root)
+
+# Except configuring task you also should:
+#  1. Create key (ssh-keygen -t dsa -b 1024), add it to remote .ssh/authorized_keys and auth system in .ssh/known_hosts
+#  2. On remote server allow named user to dump selected filesystem (zfs allow user hold,send rfsname)
+
+# If there is a global system configuration file, suck it in.
+
+if [ -r /etc/defaults/periodic.conf ]; then
+	. /etc/defaults/periodic.conf
+	source_periodic_confs
+fi
+
+echo "Synchronizing ZFS snapshots:"
+
+unwind=`readlink -nf N $0`
+. `dirname $unwind`/funcs
+
+if checkyesno daily_synczfs_enable; then
+	checknotempty daily_synczfs_servers && exit 2
+
+	checknotempty daily_synczfs_root && exit 2
+	if ! zfs list -Ht filesystem "$daily_synczfs_root" >/dev/null 2>&1; then
+		echo "  \$daily_synczfs_enable is set but \$daily_synczfs_root doesn't point to zfs filesystem."
+		exit 2
+	fi
+
+	if ! su "$daily_synczfs_user" -c : >/dev/null 2>&1; then
+		echo "  \$daily_synczfs_enable is set but \$daily_synczfs_user point to unknown or unavailable user."
+		exit 2
+	fi
+	zfs allow "$daily_synczfs_user" create,mount,receive "$daily_synczfs_root"
+
+	for server in $daily_synczfs_servers; do
+		# getting hostname, default to server name
+		eval hostname=\"\${daily_synczfs_${server}_hostname}\"
+		if [ -z $hostname ]; then
+			hostname="$server"
+		fi
+
+		# get local/remote filters
+		eval ifilter=\"\${daily_synczfs_${server}_input_filter}\"
+		eval ofilter=\"\${daily_synczfs_${server}_output_filter}\"
+
+		# check server access
+		if ! ping -oc 5 $hostname >/dev/null 2>&1; then
+			echo "  Server $server[$hostname] is mentioned in \$daily_synczfs_servers but can't be pinged."
+			exit 2
+		fi
+
+		eval aliases=\"\${daily_synczfs_${server}_fs}\"
+		for alias in $aliases; do
+			# check remote access
+			if ! su "$daily_synczfs_user" -c "ssh -oBatchMode=yes $daily_synczfs_user@$hostname :" >/dev/null 2>&1; then
+				echo "Server $server is mentioned in \$daily_synczfs_servers but provides no access."
+				exit 2
+			fi
+
+			# check remote filesystem
+			checknotempty daily_synczfs_${server}_${alias}_rfsname && exit 2
+			eval rfsname=\"\${daily_synczfs_${server}_${alias}_rfsname}\"
+			if ! echo $rfsname | grep -q '^[a-zA-Z0-9/\._-]\+$'; then
+				echo "  Server $server is mentioned but \$daily_synczfs_${server}_${alias}_rfsname [$rfsname] contains banned chars."
+				exit 2
+			elif ! su "$daily_synczfs_user" -c "ssh -oBatchMode=yes $daily_synczfs_user@$hostname \"zfs list -Ht filesystem $rfsname\"" >/dev/null 2>&1; then
+				echo "  Server $server is mentioned but \$daily_synczfs_${server}_${alias}_rfsname doesn't exist."
+				exit 2
+			fi
+
+			rsnaps=`mktemp -t synczfs`
+			su "$daily_synczfs_user" -c "ssh -oBatchMode=yes $daily_synczfs_user@$hostname \"zfs list -Hrt snapshot -d1 $rfsname\"" | awk 'BEGIN{FS="[ @\t]+"}{print$2}' > $rsnaps
+
+			# check local filesystem
+			checknotempty daily_synczfs_${server}_${alias}_fsname && exit 2
+			eval fsname=\"\${daily_synczfs_${server}_${alias}_fsname}\"
+			if ! echo $fsname | grep -q '^[a-zA-Z0-9\._-]\+$'; then
+				echo "  Server $server is mentioned in \$daily_synczfs_${server}_${alias}_fsname contains banned chars."
+				exit 2
+			elif ! zfs list -Ht filesystem $daily_synczfs_root/$fsname >/dev/null 2>&1; then
+				su "$daily_synczfs_user" -c "zfs create "$daily_synczfs_root/$fsname" ; ssh -oBatchMode=yes $daily_synczfs_user@$hostname \"zfs send -R $rfsname@`tail -1 $rsnaps` $ifilter\" $ofilter | zfs receive -Fu $daily_synczfs_root/$fsname ; zfs inherit mountpoint $daily_synczfs_root/$fsname"
+			else
+				lsnaps=`mktemp -t synczfs`
+				zfs list -Hrt snapshot -d1 "$daily_synczfs_root/$fsname" | awk 'BEGIN{FS="[ @\t]+"}{print$2}' > $lsnaps
+				common=`join $rsnaps $lsnaps | tail -1`
+				if [ -z "$common" ]; then
+					echo "  $rfsname on $server shares no snapshots with $fsname."
+					exit 2
+				else
+					# dropping local surplus
+					lastone=no
+					for snapshot in `cat $lsnaps`; do
+						if [ "_$snapshot" = "_$common" ]; then
+							lastone=yes
+							continue
+						fi
+						if [ "_$lastone" = "_yes" ]; then
+							zfs destroy "$daily_synczfs_root/$fsname@$snapshot"
+						fi
+					done
+				fi
+				rm -rf $lsnaps
+				su "$daily_synczfs_user" -c "ssh -oBatchMode=yes $daily_synczfs_user@$hostname \"zfs send -I $rfsname@$common $rfsname@`tail -1 $rsnaps` $ifilter\" $ofilter | zfs receive -F $daily_synczfs_root/$fsname"
+			fi
+			rm -rf $rsnaps
+		done
+	done
+fi