#!/bin/sh

###############################################################################
# name: zfsdumpd.sh 
#
# Script for dumping the filesystem for backup. Used in conjunection with
#  zfsrestored.sh (available on BigAdmin)
# Read full description:
#  http://www.sun.com/bigadmin/content/submitted/zfsdumpd_zfsrestored.jsp
###############################################################################

# You may change the default backup DIR in both zfsdumpd.sh and zfsrestored.sh
DIR=/var/zfsbk

Usage()
{
    cat <<-EOF

	Usage: $1 [-d backup_dir] [-r] [-z zfs]
		
        -d = where to back up 
        -r = used with -z; back up the descendents of a file system
        -z = file system to back up in format of tank/home

	EOF
}

GetBackupfileprefixFromSnapshot ()
{
    c=0
    for str in `echo $1 | awk -F@ '{print $1}' | awk -F/ '{ for( i=1 ; i <= NF ; i++ ){print $i}}`
    do
        c=`expr $c + 1`
        if [ $c -eq 1 ]
        then
            file_prefix="$str"
        else
            file_prefix="${file_prefix}_$str"
        fi
    done
    echo $file_prefix
}

BackupSnapshots ()
{
    if [ "$1" = all ]
    then
        SNAPSHOTS=`zfs list -t snapshot -o name | grep -vw NAME`
    else
        if [ $recursive -eq 0 ]
        then
            SNAPSHOTS=`zfs list -t snapshot -o name -r "$1" | grep -vw NAME`
        else
            SNAPSHOTS=`zfs list -t snapshot -o name | grep "^${1}@"`
        fi
    fi

    for snapshot in $SNAPSHOTS 
    do
        file_prefix=`GetBackupfileprefixFromSnapshot "$snapshot"` 
        if find "$DIR" -name tmp -prune -o -print | grep "${file_prefix}\." >/dev/null 2>&1
        then
            rm ${DIR}/${file_prefix}.*
        fi

        if zfs send "$snapshot" > ${DIR}/${file_prefix}.$mydate; then
            myzfs=`echo $snapshot | awk -F@ '{print $1}'`
            echo "$myzfs is backed up as ${DIR}/${file_prefix}.$mydate"
        fi
    done
}

Create_BackupSnapshots ()
{
    if [ $recursive -eq 0 ]
    then
        for snapshot in `zfs list -t snapshot -o name -r $zfs | grep -vw NAME`
        do
            zfs destroy $snapshot
        done
       
        zfs snapshot -r ${zfs}@$mydate
    else
        for snapshot in `zfs list -t snapshot -o name | grep "^${zfs}@"`
        do
            zfs destroy $snapshot
        done

        zfs snapshot ${zfs}@$mydate
    fi         

    BackupSnapshots "$zfs"
}

Create_BackupSnapshotsAll () 
{
    for snapshot in `zfs list -t snapshot -o name | grep -vw NAME`
    do
        zfs destroy $snapshot
    done
    
    for pool in `zpool list -o name | grep -vw NAME`
    do
        zfs snapshot -r ${pool}@$mydate
    done
    
    BackupSnapshots all
}

############################################################################### 
# main()
############################################################################### 

recursive=1
mydate=`date '+%Y%m%d'`

while getopts d:rz: opt
do
    case "$opt" in
    d) DIR="$OPTARG";;
    r) recursive=0;;
    z) zfs="$OPTARG";;
   \?) Usage $0 >&2; exit 2;; 
    esac
done

[ $# -ne `expr $OPTIND - 1` ] && Usage $0 && exit 2

[ -d $DIR ] || mkdir -p $DIR
 
if [ "X$zfs" != X ]
then
    if zfs list -o name | grep -v @ | grep -w "$zfs" > /dev/null
    then
        Create_BackupSnapshots 
    else
        echo File system $zfs does not exist.
        exit
    fi 
else
    Create_BackupSnapshotsAll 
fi


##############################################################################
### This script is submitted to BigAdmin by a user of the BigAdmin community.
### Sun Microsystems, Inc. is not responsible for the
### contents or the code enclosed. 
###
###
### Copyright 2008 Sun Microsystems, Inc. ALL RIGHTS RESERVED
### Use of this software is authorized pursuant to the
### terms of the license found at
### http://www.sun.com/bigadmin/common/berkeley_license.html
##############################################################################