-#!/bin/bash
-
-# Author: Carl Baldwin & Alan Pippin
-# Description: This script replicates a given zfs filesystem to a given zfs pool.
-# This script will keep all snapshots in sync, removing the ones
-# that have been deleted since the last replicate was performed.
-# This script will only send the new, or missing, snapshots since
-# the last replicate was performed.
-
-# In test mode (test=1) commands are echoed, not executed
-test=0
-
-[ $test == 0 ] && exec >> /var/log/zfs/zfs-replicate.log 2>&1
-
-# Usage: zfs-backup [filesystem] [destination_pool]
-# This script has a limitation with children under a given filesystem.
-# You must initially backup the parent filesystems first using this script
-# before backing up any of the children filesystems.
-
-fs=$1
-fs=${fs%/}
-fsname=${1#*/}
-srcpool=${1%%/*}
-srcfs="${srcpool}/$fsname"
-srcfs=${srcfs%/}
-dstpool=$2
-dstfs="${dstpool}/$srcfs"
-dstfs=${dstfs%/}
-nodstsnaps=0
-common=""
-
-if [ $test == 1 ]; then
- echo "fs: $fs"
- echo "fsname: $fsname"
- echo "srcpool: $srcpool"
- echo "srcfs: $srcfs"
- echo "dstpool: $dstpool"
- echo "dstfs: $dstfs"
-fi
-
-if ! zpool list -H "$srcpool" >/dev/null 2>&1; then
- echo >&2 "-E- The source pool, '$srcpool' doesn't seem to exist."
- exit 1
-fi
-
-if ! zpool list -H "$dstpool" >/dev/null 2>&1; then
- echo >&2 "-E- The destination pool, '$dstpool' doesn't seem to exist."
- exit 1
-fi
-
-if ! zfs list -rH -t snapshot "$dstfs" 2>&1 | grep "$dstfs@" > /dev/null 2>&1; then
- echo >&2 "-W- No snapshots detected on the destination drive for this filesystem: $dstfs"
- if zfs list -t filesystem | grep "$dstfs"; then
- echo >&2 "-I- Found zfs filesystem $dstfs on the destination pool $dstpool without any snapshots"
- echo >&2 "-I- Removing the zfs filesystem: $dstfs"
- zfs destroy "$dstfs"
- fi
- nodstsnaps=1
-fi
-
-if [ $nodstsnaps == 0 ]; then
- zfs list -rH -t snapshot $srcfs | grep "$srcfs@" | awk '{print $1}' > /tmp/source-list
- zfs list -rH -t snapshot $dstfs | grep "$dstfs@" | sed "s,$dstpool/,," | awk '{print $1}' > /tmp/destination-list
- diff -u /tmp/source-list /tmp/destination-list | grep -v '^+++' | awk '/^\+/ {print}' | sed "s,^\+,$dstpool/," > /tmp/obsolete-snapshots
- rm -f /tmp/source-list /tmp/destination-list
-
- echo >&2 "Removing obsolete backups from the destination pool"
- for snapshot in $(cat /tmp/obsolete-snapshots); do
- echo >&2 "Removing '$snapshot' from destination."
- [ $test == 0 ] && zfs destroy "$snapshot"
- done
-
- echo >&2 "Rolling back to the most recent snapshot on the destination."
- [ $test == 0 ] && zfs rollback $(zfs list -rH -t snapshot $dstfs | grep "$dstfs@" | awk '{snap=$1} END {print snap}')
-
- echo >&2 "Calculating the most recent common snapshot between the two filesystems."
- if zfs list -H "$dstfs" > /dev/null 2>&1; then
- for snap in $(zfs list -rH -t snapshot "$dstfs" | grep "$dstfs@" |
- sed 's,.*@,,' | awk '{print$1}'); do
- if zfs list -rH -t snapshot "$fs" | grep "$fs@" | sed 's,.*@,,' | awk '{print$1}' | grep "^${snap}$" >/dev/null 2>&1; then
- common=$snap
- fi
- done
- fi
-fi
-
-base=$common
-foundcommon=false
-if [ -z "$common" ]; then
- foundcommon=true
-fi
-
-for snap in $(zfs list -rH -t snapshot "$fs" | grep "$fs@" |
- sed 's,.*@,,' | awk '{print$1}'); do
- if [ "$snap" = "$common" ]; then
- foundcommon=true
- continue
- fi
-
- if $foundcommon; then
- if [ -z "$base" ]; then
- echo >&2 "Sending '$fs@$snap'"
- [ $test == 0 ] && zfs set readonly=on "$dstpool"
- [ $test == 0 ] && zfs set atime=off "$dstpool"
- [ $test == 0 ] && zfs set sharenfs=off "$dstpool"
- [ $test == 0 ] && zfs set mountpoint=legacy "$dstpool"
- [ $test == 0 ] && zfs send "$fs@$snap" | zfs recv -v "$dstfs"
- else
- echo >&2 "Sending '$fs@$base' -> '$fs@$snap'"
- [ $test == 0 ] && zfs send -i "$fs@$base" "$fs@$snap" | zfs recv -v "$dstfs"
- fi
- base=$snap
- fi
-done
-
-true