#! /bin/ksh

# * CDDL HEADER START
# *
# * The contents of this file are subject to the terms of the
# * Common Development and Distribution License (the "License").
# * You may not use this file except in compliance with the License.
# *
# * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
# * or http://www.opensolaris.org/os/licensing.
# * See the License for the specific language governing permissions
# * and limitations under the License.
# *
# * When distributing Covered Code, include this CDDL HEADER in each
# * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
# * If applicable, add the following below this CDDL HEADER, with the
# * fields enclosed by brackets "[]" replaced with your own identifying
# * information: Portions Copyright [yyyy] [name of copyright owner]
#
snap_name ()
{
    SN=`date '+%S.%M.%H.%d.%m.%y'`
    echo "SNAPSHOT-"$SN
}

# ssh-keygen -t rsa
# cat id_rsa.pub >> authorized_keys2
# scp id_rsa.pub remotehostname:/.ssh/remotehostname.key.pub
#
# In /etc/ssh/sshd_config
# PermitRootLogin yes

REMOTEHOST=va64-x2200b-gmp03
LOCALPOOL=zpool
REMOTEPOOL=zpool_backup
FS=fs1
REMOTEFS=sn1

# Unadjusted Interval is the wait between snapshots
INTERVAL=60  
integer ADJUSTED_INTERVAL
ENCRYPT="-c blowfish"


SNAP_NAME=`snap_name`

# Take a snapshot
zfs snapshot -r $LOCALPOOL/$FS@$SNAP_NAME

if [ $? != 0 ] ; then
    echo "snapshot failed $SNAP_NAME"
    exit 1
fi

# Test if the remote directory is already there
ssh $REMOTEHOST ls /$REMOTEPOOL/$REMOTEFS 2>&1 > /dev/null 

# If it is not then do a full send/recv and wait, and wait, and wait, and wait
if [ $? != 0 ] ; then
    printf "Full snapshot send/recv started : %s\n" "`date`"
    zfs send  $LOCALPOOL/$FS@$SNAP_NAME |  ssh $ENCRYPT $REMOTEHOST zfs recv -v $REMOTEPOOL/$REMOTEFS
else 
    zfs send -i $1 $LOCALPOOL/$FS@$SNAP_NAME |  ssh $ENCRYPT $REMOTEHOST zfs recv -F -v $REMOTEPOOL/$REMOTEFS
fi

if [ $? != 0 ] ; then
    echo "send/recv failed $SNAP_NAME"
    exit 1
fi

PREVIOUS_SN=$SNAP_NAME

sleep 1

while true
do
    echo ""
    SECONDS=0
    SNAP_NAME=`snap_name`

    zfs snapshot -r $LOCALPOOL/$FS@$SNAP_NAME
    if [ $? != 0 ] ; then
        echo "snapshot failed $SNAP_NAME"
        exit 1
    fi
    # Now apply the incremental
    printf "Incremental snapshot send/recv started : %s\n" "`date`"
    zfs send -i $PREVIOUS_SN $LOCALPOOL/$FS@$SNAP_NAME |  ssh $ENCRYPT $REMOTEHOST zfs receive -v $REMOTEPOOL/$REMOTEFS
 
    if [ $? != 0 ] ; then
        echo "send/recv failed for $SNAP_NAME"
        exit 1
    fi
    printf "snapshot send/recv completed : "

    if [ $SECONDS -ge $INTERVAL ] ; then
                echo "zfs send/recv too longer than $INTERVAL"
                echo "No point sleeping"
                echo "Review data rate vs sleep time (buy faster network!)"
    else
                ((ADJUSTED_INTERVAL=INTERVAL-SECONDS))
		printf "zfs send/recv took %u seconds : " $SECONDS
                printf  "Adjusted delay interval = %u seconds\n" $ADJUSTED_INTERVAL
                sleep $ADJUSTED_INTERVAL
    fi

    PREVIOUS_SN=$SNAP_NAME
done