innodb_buffer_pool_size not changed I use MySQL  5.5.23-1~dotdeb.0 (Debian) and here is the relevant part of my.cnf

default-storage-engine = innodb
innodb_buffer_pool_size = 3G
innodb_log_file_size = 256M
innodb_thread_concurrency = 8
innodb_flush_method = O_DIRECT
innodb_file_per_table = 1
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 4M
innodb_additional_mem_pool_size = 20M


The problem is that no matter what value I choose for innodb_buffer_pool_size (I tried also 4G and 8G and 8000M). I get the following from mysql&gt; SHOW global  VARIABLES;

| innodb_buffer_pool_size | 134217728  


Result from the Tuning primer script:

INNODB STATUS
Current InnoDB index space = 621 M
Current InnoDB data space = 3.82 G
Current InnoDB buffer pool free = 0 %
Current innodb_buffer_pool_size = 128 M
Depending on how much space your innodb indexes take up it may be safe
to increase this value to up to 2 / 3 of total system memory 


I appreciate your hints to fix this.
Ok, thanks this answer I figured out that I needed to put the config WITHIN [mysqld] block in my.cnf to take effect. 

My mistake was that I just had appended the commands at the end of my.cnf file.

Then at mysql restart I encounterd

InnoDB: Error: log file ./ib_logfile0 is of different size 0 5242880 bytes


To resolve this error, I needed to deleted log 


  rm -f /var/lib/mysql/ib_logfile[01]


and restart as Rolando told here.