reduce MySQL memory usage

* add informations about innodb_buffer tweaking

etc/mysql/my.cnf

@@ -49,24 +49,24 @@ max_connections		= 100
 connect_timeout		= 5
 wait_timeout		= 60
 max_allowed_packet	= 16M
-thread_cache_size       = 128
+thread_cache_size   = 128
 sort_buffer_size	= 4M
 bulk_insert_buffer_size	= 16M
-tmp_table_size		= 64M
-max_heap_table_size	= 64M
+tmp_table_size		= 32M
+max_heap_table_size	= 32M
 #
 # * MyISAM
 #
 # This replaces the startup script and checks MyISAM tables if needed
 # the first time they are touched. On error, make copy and try a repair.
 myisam_recover_options = BACKUP
-key_buffer_size		= 128M
-open-files-limit	= 500000
-table_open_cache	= 500000
-myisam_sort_buffer_size	= 512M
-concurrent_insert	= 2
-read_buffer_size	= 2M
-read_rnd_buffer_size	= 1M
+key_buffer_size		 = 64M
+open-files-limit	 = 500000
+table_open_cache	 = 500000
+myisam_sort_buffer_size	= 256M
+concurrent_insert	 = 2
+read_buffer_size	 = 2M
+read_rnd_buffer_size = 1M
 #
 # * Query Cache Configuration
 #
@@ -129,9 +129,14 @@ log_slow_verbosity	= query_plan
 # Read the manual for more InnoDB related options. There are many!
 default_storage_engine	= InnoDB
 # you can't just change log file size, requires special procedure
-innodb_log_file_size	= 256M
-innodb_buffer_pool_size	= 2G
-innodb_log_buffer_size	= 512M
+
+# innodb_log_file_size = innodb_buffer_pool_size / 8
+innodb_log_file_size	= 128M
+# innodb_buffer_pool_size = RAM / 2
+innodb_buffer_pool_size	= 1G
+# innodb_log_buffer_size = innodb_buffer_pool_size / 4
+innodb_log_buffer_size	= 256M
+
 innodb_file_per_table	= 1
 innodb_open_files	= 500000
 innodb_io_capacity	= 500000