#!/bin/bash
-: Usage: zfs-backup [filesystem] [destination_pool]
+# Author: Carl Baldwin & Alan Pippin
+# Description: This script replicates a remote zfs filesystem to a local 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.
+# Usage: replicate <hostname> <zfs filesystem>
-tmpdir="/export/home/tmp"
+# source our configuration
+config="${0%/*}/zfs-scripts.conf"
+[ -e "${config}.dist" ] && . ${config}.dist
+[ -e "${config}" ] && . ${config}
-lockdir="/tmp/zfs-admin-lock"
-if ! mkdir "$lockdir" >/dev/null 2>&1; then
- echo >&2 "ZFS admin lock directory is present."
- exit 1
-fi
+# command line arg parsing
+remote=$1
+remote_fs=$2
+remote_pool=${2%%/*}
-cleanup() { rm -rf "$lockdir"; }
+# Setup our cleanup and exit trap
+cleanup() {
+ if [[ -e "$local_list" ]]; then
+ rm -f $local_list
+ fi
+ if [[ -e "$remote_list" ]]; then
+ rm -f $remote_list
+ fi
+ $ssh $remote ls -d "$lockdir" > /dev/null 2>&1
+ if [[ $? == 0 ]]; then
+ $ssh $remote rm -rf "$lockdir"
+ fi
+}
+fatal_and_exit() {
+ echo -e 2>&1 "$1"
+ # Destroy the current backup markers from the local backup_pool and remote_pool if they exist
+ if [[ -n "$current_backup_marker" ]]; then
+ # Local backup pool current backup marker
+ $zfs list -t snapshot ${backup_pool}/${current_backup_marker} > /dev/null 2>&1
+ if [ $? == 0 ]; then
+ $zfs destroy ${backup_pool}/${current_backup_marker}
+ fi
+ # Remote pool current backup marker
+ $ssh $remote zfs list -t snapshot ${current_backup_marker} > /dev/null 2>&1
+ if [ $? == 0 ]; then
+ $ssh $remote $zfs destroy ${current_backup_marker}
+ fi
+ fi
+ # send email notification
+ if [[ -n "$2" ]]; then
+ echo -e "$1" | $mailx -s "zfs replicate on $hostname failed" "$2"
+ fi
+ # exit
+ exit 1
+}
+trap fatal_and_exit INT
trap cleanup EXIT
-fs=$1
-sourcepool=${1%%/*}
-fsname=${1#*/}
-destinationpool=$2
+# Declare a function to handle the replicate operation
+replicate() {
+ zfs_send="$1"
+ zfs_recv="$zfs receive -vF -d ${backup_pool}/${remote_pool}"
+ glue="$throttle $throttle_opt"
+ if [[ $throttle_enable == 1 && -e $throttle ]]; then
+ # handle using the glue in the local and remote host case properly
+ if [[ -z "$ssh" ]]; then
+ # local host glue case
+ $zfs_send | $glue | $zfs_recv
+ else
+ # remote host glue case
+ $ssh $remote "$zfs_send | $glue" | $zfs_recv
+ fi
+ else
+ # no glue case - works for both the local and remote host cases
+ $ssh $remote $zfs_send | $zfs_recv
+ fi
+ # The return code of the zfs_send | zfs_recv operation will be returned to the caller
+}
-if ! zpool list -H "$sourcepool" >/dev/null 2>&1; then
- echo >&2 "The source pool, '$sourcepool' doesn't seem to exist."
- exit 1
+# Make sure we have valid arguments
+if [[ -z "$remote" ]] || [[ -z "$remote_fs" ]]; then
+ fatal_and_exit "Usage: $0 <hostname> <zfs filesystem>"
fi
-if ! zpool list -H "$destinationpool" >/dev/null 2>&1; then
- echo >&2 "The destination pool, '$destinationpool' doesn't seem to exist."
- exit 1
+# check for localhost
+if [[ $remote = "localhost" ]]; then
+ remote=""
+ ssh=""
fi
-if ! zfs list -H "$fs" >/dev/null 2>&1; then
- echo >&2 "The source filesytem, '$fs' doesn't seem to exist."
- exit 1
+# Make sure the local backup pool and local receiving filesystem exist, or print some errors
+zpool list -H "$backup_pool" >/dev/null 2>&1
+if [ $? != 0 ]; then
+ fatal_and_exit "-E- The local backup pool on $hostname, '$backup_pool' doesn't seem to exist." $mailto
+fi
+zfs list "$backup_pool/$remote_pool" >/dev/null 2>&1
+if [ $? != 0 ]; then
+ echo >&2 "-I- The local filesystem for the remote pool, '$backup_pool/$remote_pool' doesn't seem to exist."
+ echo >&2 " Creating the local filesystem to receive the remote pool into: $backup_pool/$remote_pool"
+ $zfs create $backup_pool/$remote_pool
+ if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote $zfs on $hostname create command failed" $mailto
+ fi
fi
-printsnaps() {
-sed 's,.*/,,' | awk '{print $1}'
-}
+# Obtain the zpool guid for the local backup pool
+backup_pool_guid=`zpool get guid $backup_pool 2>&1 | grep $backup_pool | awk '{ print $3 }'`
+zpool get guid $backup_pool > /dev/null 2>&1
+if [ $? != 0 ]; then
+ fatal_and_exit "-E- Unable to extract the guid for the local backup pool on $hostname: $backup_pool" $mailto
+fi
-zfs list -rH -t snapshot $sourcepool/$fsname | printsnaps > /tmp/source-list
-zfs list -rH -t snapshot $destinationpool/$fsname | printsnaps > /tmp/destination-list
-diff -u /tmp/source-list /tmp/destination-list | grep -v '^+++' | awk '/^\+/ {print}' | sed "s,^\+,$destinationpool/," > /tmp/obsolete-snapshots
-rm -f /tmp/source-list /tmp/destination-list
+# Turn on shell verbosity
+set -x
-echo >&2 "Removing obsolete backups from the destination pool"
-for snapshot in $(cat /tmp/obsolete-snapshots); do
- echo >&2 "Removing '$snapshot' from destination."
- zfs destroy "$snapshot"
+# Create the remote lockdir before continuing with the replicate
+# Spinlock on creating the lock
+maxsleeptime=60
+maxattempts=500
+attempts=0
+while true; do
+ $ssh $remote mkdir "$lockdir" >/dev/null 2>&1
+ if [ $? != 0 ]; then
+ # Another zfs admin tool is running.
+ # Wait a random amount of time and try again
+ ransleep=$(($RANDOM % $maxsleeptime))
+ sleep $ransleep
+ ((attempts=attempts+1))
+ else
+ # No other zfs admin tool is running, we can now.
+ break
+ fi
+ if [[ $attempts -gt $maxattempts ]]; then
+ # We've exceeded our maximum while loop count
+ echo "-E- The zfs filesystem has been locked down. Skipping replicate operation."
+ fail_msg=`$ssh $remote ls -ld $lockdir 2>&1`
+ fatal_and_exit "zfs-replicate-all on $hostname unable to obtain zfs admin lock:\n$fail_msg" $mailto
+ fi
done
-echo >&2 "Rolling back to the most recent snapshot on the destination."
-zfs rollback $(zfs list -rH -t snapshot $destinationpool/$fsname | awk '{snap=$1} END {print snap}')
+# Setup our backup marker names
+current_backup_marker=${remote_fs}@current-backup-${backup_pool_guid}
+previous_backup_marker=${remote_fs}@previous-backup-${backup_pool_guid}
-echo >&2 "Calculating the most recent common snapshot between the two filesystems."
-common=""
-if zfs list -H "$destinationpool/$fsname" >/dev/null 2>&1; then
- for snap in $(zfs list -rH -t snapshot "$destinationpool/$fsname" |
- sed 's,.*@,,' | awk '{print$1}'); do
- if zfs list -rH -t snapshot "$fs" | sed 's,.*@,,' | awk '{print$1}' | grep "^${snap}$" >/dev/null 2>&1; then
- common=$snap
- fi
- done
+# List the snapshots on the remote machine.
+remote_list=$(mktemp /tmp/replicate.XXXXXX)
+$ssh $remote \
+ $zfs list -H -t snapshot |
+ grep ^${remote_fs}@ |
+ awk '{print$1}' > $remote_list
+if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote $zfs list on $hostname command failed" $mailto
fi
-base=$common
-foundcommon=false
-if [ -z "$common" ]; then
- foundcommon=true
+# List the snapshots on the local machine.
+# Don't list the current backup marker if it exists on the local side.
+# If you do, it can mess up the common finding algorithm below.
+local_list=$(mktemp /tmp/replicate.XXXXXX)
+$zfs list -H -t snapshot |
+ grep ^${backup_pool}/${remote_fs}@ |
+ grep -v ^${backup_pool}/${current_backup_marker} |
+ awk "{gsub(/^$backup_pool./,\"\",\$1); print\$1}" > $local_list
+if [ $? != 0 ]; then
+ fatal_and_exit "-E- local $zfs list on $hostname command failed" $mailto
fi
-for snap in $(zfs list -rH -t snapshot "$fs" |
- sed 's,.*@,,' | awk '{print$1}'); do
- if [ "$snap" = "$common" ]; then
- foundcommon=true
- continue
+# Destroy the current backup marker snapshot on the remote system if it exists
+grep -q ${current_backup_marker} $remote_list
+if [ $? == 0 ]; then
+ $ssh $remote $zfs destroy ${current_backup_marker}
+ if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote $zfs destroy on $hostname command failed" $mailto
fi
+fi
- if $foundcommon; then
- if [ -z "$base" ]; then
- echo >&2 "Sending '$1/$snap'"
- zfs send "$1@$snap" > $tmpdir/zfs.part
- mv $tmpdir/zfs.part $tmpdir/zfs.data
- zfs recv "$destinationpool/$fsname" < $tmpdir/zfs.data
- rm -f $tmpdir/zfs.data
- zfs set readonly=on "$destinationpool"
- zfs set atime=off "$destinationpool"
- zfs set sharenfs=off "$destinationpool"
- zfs set mountpoint=legacy "$destinationpool"
- zfs unmount "$destinationpool/$fsname"
- zfs rollback "$destinationpool/$fsname@$snap"
- else
- echo >&2 "Sending '$1@$base' -> '$1/$snap'"
- zfs send -i "$1@$base" "$1@$snap" > $tmpdir/zfs.part
- mv $tmpdir/zfs.part $tmpdir/zfs.data
- zfs recv "$destinationpool/$fsname" < $tmpdir/zfs.data
- rm -f $tmpdir/zfs.data
- # zfs unmount "$destinationpool/$fsname"
- # zfs rollback "$destinationpool/$fsname@$snap"
+# Create the current backup marker snapshot on the remote system
+$ssh $remote $zfs snapshot ${current_backup_marker}
+if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote $zfs snapshot on $hostname command failed" $mailto
+fi
+
+# Check to see if the previous backup marker exists in the remote snapshot list.
+# Check to see if the previous backup marker exists in the local snapshot list.
+# If the previous backup markers exists, perform an incremental replicate. Else:
+# 1) check to see if a common snapshot exists, and perform an incremental replicate.
+# 2) if no common snapshot exists, destroy the local filesystem, and perform a full replicate.
+grep -q ${previous_backup_marker} $remote_list
+no_markers=$?
+grep -q ${previous_backup_marker} $local_list
+no_markers=$(($no_markers || $?))
+
+if [ $no_markers == 0 ]; then
+ # We found backup markers, incrementally send the new snaps
+
+ # First, rollback the local backup pool to the previous backup marker in case the previous
+ # backup was interrupted for some reason. If we don't do this, the zfs send -R command
+ # below may complain about snaps already existing as it tries to resend from the
+ # previous backup marker again from a previously interrupted replicate.
+ $zfs rollback -r ${backup_pool}/${previous_backup_marker}
+ if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote incremental $zfs rollback command failed on $hostname" $mailto
+ fi
+ # Now it should be safe to send the snaps
+ replicate "$zfs send -Rc -I${previous_backup_marker} ${current_backup_marker}"
+ if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote incremental $zfs send command failed on $hostname" $mailto
+ fi
+else
+ # We didn't find any backup markers, next check to see if we have a common snapshot.
+
+ # See what the most recent snapshot on the remote end is.
+ latest=$(tail -n 1 $remote_list)
+
+ # I did this to make sure that diff would always display the most recent common
+ # Since we're keying off the context of the diff, we need to ensure we will get context
+ # by injecting a known difference in case no others exist in the lists.
+ echo bogus.remote >> $remote_list
+ echo bogus.local >> $local_list
+ common=$(diff -u $remote_list $local_list | grep '^ ' | tail -n 1)
+
+ if [[ -n "$common" ]]; then
+ # We found a common snapshot, incrementally send the new snaps
+ replicate "$zfs send -Rc -I${common/*@/@} ${current_backup_marker}"
+ if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote incremental $zfs send command failed on $hostname" $mailto
+ fi
+ else
+ # We did not find any markers or a common snapshot
+ # At this point, we'll have to send the entire filesystem
+ # Destroy the local filesystem if it exists before receving the full replicate
+ zfs list ${backup_pool}/${remote_fs} > /dev/null 2>&1
+ if [ $? == 0 ]; then
+ if [[ $destroy_local_filesystem_on_full_replicate == 1 ]]; then
+ $zfs destroy -r ${backup_pool}/${remote_fs}
+ if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote full $zfs destroy command failed on $hostname" $mailto
+ fi
+ else
+ echo "-W- We need to destroy a local filesystem before receiving a full stream."
+ echo " However, since the option is set to prevent this, skipping replicate operation."
+ fatal_and_exit "unable to destroy local filesystem:\n$zfs destroy -r ${backup_pool}/${remote_fs} not able to run on $hostname" $mailto
+ fi
+ fi
+ # Send the full filesystem
+ replicate "$zfs send -Rc ${current_backup_marker}"
+ if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote full $zfs send command failed on $hostname" $mailto
fi
- base=$snap
fi
-done
+fi
+
+# destroy the previous backup markers now that we've replicated past them
+# don't check the return codes here because these may not exist, and that is ok
+$zfs destroy ${backup_pool}/${previous_backup_marker} > /dev/null 2>&1
+$ssh $remote $zfs destroy ${previous_backup_marker} > /dev/null 2>&1
-true
+# Rename the current backup marker to be the previous backup marker
+$zfs rename ${backup_pool}/${current_backup_marker} ${backup_pool}/${previous_backup_marker}
+if [ $? != 0 ]; then
+ fatal_and_exit "-E- local $zfs rename command failed on $hostname" $mailto
+fi
+$ssh $remote $zfs rename ${current_backup_marker} ${previous_backup_marker}
+if [ $? != 0 ]; then
+ fatal_and_exit "-E- remote $zfs rename command failed on $hostname" $mailto
+fi
projects / zfs-ubuntu / .git / blobdiff