Simple backup script

[Panchux]

I was looking to make a very simple (yet effective) backup script for Zimbra CS.
I know there are a lot of versions here in the forum but they seem not to generate easily recover backups. So I made this

#!/bin/bash
#this is where I will store the backup files outside the server
mount //131.107.2.151/PUBLIC /media/mybookworld -o username=root,password=somepass
/etc/init.d/zimbra stop
# this is for freeing cache
echo 3 > /proc/sys/vm/drop_caches
# now I make a directory called after the date
mkdir /home/administrador/zimbra/`date +%Y%m%d`
# and I use rsync to create an exact copy
rsync -avHK /opt/zimbra/ /home/administrador/zimbra/`date +%Y%m%d`
# I start again all services
/etc/init.d/zimbra start
cd /home/administrador/zimbra/
# now I free some disk space deleting the oldest backup directory
ls | head -1 | xargs rm -r
# make a tarball
tar -cf /home/administrador/zimbra/`date +%Y%m%d`.tar /home/administrador/`date +%Y%m%d`
# compress it
gzip `date +%Y%m%d`.tar
# split it and save it in a network disk
split -d -b4400m /home/administrador/zimbra/`date +%Y%m%d`.tar.gz /media/mybookworld/zimbra/`date +%Y%m%d`.tar.gz.
# now I create a file with the md5 checksum of each archive for later reference
find /home/administrador/zimbra/`date +%Y%m%d`.tar.gz.* -type f -print0 | xargs -0 md5sum > /media/mybookworld/zimbra/`date +%Y%m%d`.md5

This is executed at late night hours when server is almost idle.

The question is: in case of failure would the copy of /opt/zimbra made this way be enough to restore the server?

This might be a silly question but I was not able (and I hope I won't have ) to test it in a real situation.

Thanks,

Pancho