#!/bin/bash

#
# MySQL-Backup mit LVM-SnapShot
#

#------------------------------------------------------------------------------#
#
# https://www.badllama.com/content/mysql-backups-using-lvm-snapshots
#
#------------------------------------------------------------------------------#
# LVM2, und rsnapshot muss installiert sein
# aptitude install lvm2 rsnapshot
# eine Volumengruppe muss angelegt sein,
# in der das zu sichernde Laufwerk liegt und soviel freier Platz ist,
# wie temporär für die Backup-Zeit benötigt werden.
#------------------------------------------------------------------------------#
VERSION="v2017022300"
#
# /dev/mapper/backup-backup       /var/cache/rsnapshot    ext4    errors=remount-ro 0       0
# /dev/mapper/trusty-mysqlbackup  /snapshot               ext4    errors=remount-ro 0       0
#
SNAPSHOT="/snapshot"
VolumenGruppe="trusty"
VolumenName="mysql"
#------------------------------------------------------------------------------#

BACKUP=Ja
umount /var/cache/rsnapshot 2>/dev/null
umount ${SNAPSHOT} 2>/dev/null

echo "FLUSH TABLES WITH READ LOCK;" | mysql -t || export BACKUP=Nein
echo "SHOW MASTER STATUS; SHOW SLAVE HOSTS; SHOW SLAVE STATUS \G;" | mysql -t > /var/lib/mysql/data/MASTER_STATUS.txt || export BACKUP=Nein
# modprobe dm-snapshot
lvcreate -l 100%FREE -s -n ${VolumenName}backup /dev/${VolumenGruppe}/${VolumenName} || export BACKUP=Nein
echo "UNLOCK TABLES;" | mysql -t

mount /dev/mapper/backup-backup       /var/cache/rsnapshot   || export BACKUP=Nein
mount /dev/${VolumenGruppe}/${VolumenName}backup ${SNAPSHOT} || export BACKUP=Nein

if [ "${BACKUP}" = Ja ] ; then
        #
        # Copy data to backup
        rsnapshot hourly
        #
fi

ls -lha /var/cache/rsnapshot/backup/
umount /var/cache/rsnapshot
umount ${SNAPSHOT}
lvremove -f /dev/${VolumenGruppe}/${VolumenName}backup