#!/bin/bash
# $Id: zfs-backup,v 1.2 2014/12/09 04:26:50 friedman Exp $

# To initialize iscsi target:
#	iscsiadm modify initiator-node --node-name iqn.1995-06.com.splode:prv.file-server
# 	iscsiadm modify discovery --static enable --sendtargets enable --iSNS enable
#
# 	iscsiadm add isns-server isns.prv.splode.com
#	iscsiadm add discovery-address readynas-nv.prv.splode.com
#
# To bring iscsi backup pool online:
# 	svcadm enable svc:/network/iscsi/initiator:default
# 	zpool import [poolname]
#
# To take offline:
# 	zpool export [poolname]
# 	svcadm disable svc:/network/iscsi/initiator:default
#

lastsnap()
{
  zfs list -t snapshot -H -d 1 -o name -S name $1 \
   | sed -e '/@backup\./!d' \
         -e 's/.*@//' \
         -e q
}

mksnap()
{
  name=backup.`date +"%Y-%m-%d.%H:%M:%S"`
  zfs snapshot -r $1@$name
  echo $name
}

fslist()
{
  zfs list -H -r -o name "$@"
}

backup()
{
  srcpool=$1
  dstpool=$2

  oldsnap=`lastsnap $srcpool`
  newsnap=`mksnap $srcpool`

  for fs in `fslist $srcpool`; do
    echo Backing up $fs
    time { zfs send -I $oldsnap $fs@$newsnap | zfs recv -F -v -d $dstpool; }
  done
}

main()
{
  case $# in
    2 ) : ;;
    * ) echo "Usage: ${0##*/} [srcpool] [dstpool]" 1>&2
        exit 1 ;;
  esac

  PATH=/usr/gnu/bin:/sbin:$PATH

  backup "$@"
}

main "$@"

# eof