zfs-replicate

   1 #!/bin/bash
   2
   3 : Usage: zfs-backup [filesystem] [destination_pool]
   4
   5 tmpdir="/export/home/tmp"
   6
   7 lockdir="/tmp/zfs-admin-lock"
   8 if ! mkdir "$lockdir" >/dev/null 2>&1; then
   9   echo >&2 "ZFS admin lock directory is present."
  10   exit 1
  11 fi
  12
  13 cleanup() { rm -rf "$lockdir"; }
  14 trap cleanup EXIT
  15
  16 fs=$1
  17 sourcepool=${1%%/*}
  18 fsname=${1#*/}
  19 destinationpool=$2
  20
  21 if ! zpool list -H "$sourcepool" >/dev/null 2>&1; then
  22   echo >&2 "The source pool, '$sourcepool' doesn't seem to exist."
  23   exit 1
  24 fi
  25
  26 if ! zpool list -H "$destinationpool" >/dev/null 2>&1; then
  27   echo >&2 "The destination pool, '$destinationpool' doesn't seem to exist."
  28   exit 1
  29 fi
  30
  31 if ! zfs list -H "$fs" >/dev/null 2>&1; then
  32   echo >&2 "The source filesytem, '$fs' doesn't seem to exist."
  33   exit 1
  34 fi
  35
  36 printsnaps() {
  37 sed 's,.*/,,' | awk '{print $1}'
  38 }
  39
  40 zfs list -rH -t snapshot $sourcepool/$fsname | printsnaps > /tmp/source-list
  41 zfs list -rH -t snapshot $destinationpool/$fsname | printsnaps > /tmp/destination-list
  42 diff -u /tmp/source-list /tmp/destination-list | grep -v '^+++' | awk '/^\+/ {print}' | sed "s,^\+,$destinationpool/," > /tmp/obsolete-snapshots
  43 rm -f /tmp/source-list /tmp/destination-list
  44
  45 echo >&2 "Removing obsolete backups from the destination pool"
  46 for snapshot in $(cat /tmp/obsolete-snapshots); do
  47   echo >&2 "Removing '$snapshot' from destination."
  48   zfs destroy "$snapshot"
  49 done
  50
  51 echo >&2 "Rolling back to the most recent snapshot on the destination."
  52 zfs rollback $(zfs list -rH -t snapshot $destinationpool/$fsname | awk '{snap=$1} END {print snap}')
  53
  54 echo >&2 "Calculating the most recent common snapshot between the two filesystems."
  55 common=""
  56 if zfs list -H "$destinationpool/$fsname" >/dev/null 2>&1; then
  57   for snap in $(zfs list -rH -t snapshot "$destinationpool/$fsname" |
  58                   sed 's,.*@,,' | awk '{print$1}'); do
  59     if zfs list -rH -t snapshot "$fs" | sed 's,.*@,,' | awk '{print$1}' | grep "^${snap}$" >/dev/null 2>&1; then
  60       common=$snap
  61     fi
  62   done
  63 fi
  64
  65 base=$common
  66 foundcommon=false
  67 if [ -z "$common" ]; then
  68   foundcommon=true
  69 fi
  70
  71 for snap in $(zfs list -rH -t snapshot "$fs" |
  72                 sed 's,.*@,,' | awk '{print$1}'); do
  73   if [ "$snap" = "$common" ]; then
  74     foundcommon=true
  75     continue
  76   fi
  77
  78   if $foundcommon; then
  79     if [ -z "$base" ]; then
  80       echo >&2 "Sending '$1/$snap'"
  81       zfs send "$1@$snap" > $tmpdir/zfs.part
  82       mv $tmpdir/zfs.part $tmpdir/zfs.data
  83       zfs recv "$destinationpool/$fsname" < $tmpdir/zfs.data
  84       rm -f $tmpdir/zfs.data
  85       zfs set readonly=on "$destinationpool"
  86       zfs set atime=off "$destinationpool"
  87       zfs set sharenfs=off "$destinationpool"
  88       zfs set mountpoint=legacy "$destinationpool"
  89       zfs unmount "$destinationpool/$fsname"
  90       zfs rollback "$destinationpool/$fsname@$snap"
  91     else
  92       echo >&2 "Sending '$1@$base' -> '$1/$snap'"
  93       zfs send -i "$1@$base" "$1@$snap" > $tmpdir/zfs.part
  94       mv $tmpdir/zfs.part $tmpdir/zfs.data
  95       zfs recv "$destinationpool/$fsname" < $tmpdir/zfs.data
  96       rm -f $tmpdir/zfs.data
  97       # zfs unmount "$destinationpool/$fsname"
  98       # zfs rollback "$destinationpool/$fsname@$snap"
  99     fi
 100     base=$snap
 101   fi
 102 done
 103
 104 true