at the moment mysqldump (22 minutes exec time, 5 GB Dump), when to use xtrabackup? We use the Puppet code for deploying MariaDB. Those are the backup options.


mysql::backup::mysqldump: Implements mysqldump backups.
mysql::backup::mysqlbackup: Implements backups with Oracle MySQL
Enterprise Backup. 
mysql::backup::xtrabackup: Implements backups with
XtraBackup from Percona.


We don't own MySQL Enterprise Backup licenses.

Here the backup script. The big problem at the moment, we don't notice when backup is failing.

#!/bin/bash
#
# MySQL Backup Script
#  Dumps mysql databases to a file for another backup tool to pick up.
#
# MySQL code:
# GRANT SELECT, RELOAD, LOCK TABLES ON *.* TO 'user'@'localhost'
# IDENTIFIED BY 'password';
# FLUSH PRIVILEGES;
#
##### START CONFIG ###################################################

USER=backup
DIR=/var/lib/mysql/backup
ROTATE=6

# Use a pwd file. See https://dev.mysql.com/doc/refman/5.1/en/password-security-user.html
PWD_FILE=$(mktemp ${DIR}/backup.cnf.XXXX)
echo "
[client]
password=sirugrwiuwiuwguisrkogos
" &gt;&gt; $PWD_FILE

PREFIX=mysql_backup_

ADDITIONAL_OPTIONS="--ignore-table=mysql.event"


##### STOP CONFIG ####################################################
PATH=/usr/bin:/usr/sbin:/bin:/sbin



set -o pipefail

cleanup()
{
    find "${DIR}/" -maxdepth 1 -type f -name "${PREFIX}*.sql*" -mtime +${ROTATE} -print0 | xargs -0 -r rm -f
}

mysqldump --defaults-file=${PWD_FILE} -u${USER} --opt --flush-logs --single-transaction \
 ${ADDITIONAL_OPTIONS} \
 --all-databases | bzcat -zc &gt; ${DIR}/${PREFIX}`date +%Y%m%d-%H%M%S`.sql.bz2

if [ $? -eq 0 ] ; then
    cleanup
fi


rm -rf $PWD_FILE


backup time

# time /usr/local/sbin/mysqlbackup.sh

real    21m35.647s
user    20m47.059s
sys     0m7.843s


backup size

# du -sh mysql_backup_20160223-123920.sql
4.9G    mysql_backup_20160223-123920.sql


Is it in our use case better to use xtrabackup? When to use xtrabackup?
Can't you test this on a test machine? I don't mean to be rude, but only you can really tell if XtraBackup is better  for you. What I do know is that  Percona is a quality outfit and that their offerings are always worth a look. 

I'm guessing about your scenario, but any backup will depend more on your disk config than on a particular programme (RAID config &amp;c.). There are four things to be considered in any IT setup - hardware, networking, OS and software (and maybe 5 - people :-) ).

Have you also looked at MyLVMBackup? Zmanda? If you're considering XtraBackup, you must be on Linux - these also work on that platform.