Comment 1 for bug 1352865

This causes the following problem
 xtrabackup --defaults-file=/etc/my.cnf.d/server.cnf --backup --target-dir=/usr/aih/autobackup/CTM/nxi
xtrabackup version 2.2.3 based on MySQL server 5.6.17 Linux (x86_64) (revision id: )
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /var/lib/mysql/nxi
xtrabackup: open files limit requested 0, set to 1024
xtrabackup: using the following InnoDB configuration:
xtrabackup: innodb_data_home_dir = ./
xtrabackup: innodb_data_file_path = ibdata1:10M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 2
xtrabackup: innodb_log_file_size = 50331648
InnoDB: Error: log file ./ib_logfile0 is of different size 268435456 bytes
InnoDB: than specified in the .cnf file 50331648 bytes!

As it fails to read the mariadb section of the server.cnf
[mariadb]

innodb_file_per_table = 1
innodb_buffer_pool_size = 1G
innodb_log_file_size=256M
innodb_log_buffer_size=4M
max_allowed_packet=1048576000
max_connections=300
wait_timeout=300
interactive_timeout=300
thread_handling=pool-of-threads #Enable Thread Pool
thread_pool_size=20 #Recommended Thread Pool size for OLTP
extra_port=3386 #Alternate port to login if threadpool has locked up
extra_max_connections=3 #Allowed number of connections to use extra port

Would have been good to have a note about this on the documentation page to warn of this simple configuration errror until it is resolved, it would have saved a few hours of troubleshooting