my database server has 132G RAM. So based on what I have read so far, I have set innodb-buffer-pool-sizein my.cnf to 112G (80% of RAM)
# INNODB #
innodb-flush-method = O_DIRECT
innodb-log-files-in-group = 2
innodb-log-file-size = 512M
innodb-flush-log-at-trx-commit = 1
innodb-file-per-table = 1
innodb-buffer-pool-size = 112G
Eventhough I have set the innodb-buffer-pool-size to 112G in my.cnf, the value seen in database is 120259084288 (120G). I am assuming this is happening b'cos the default value for innodb_buffer_pool_chunk_size is 134217728 and the innodb_buffer_pool_instances is 8. Any idea why mysql is setting the innodb_buffer_pool_size to a higher value that what I have specified?
mysql> show variables like 'innodb_buffer%';
+-------------------------------------+----------------+
| Variable_name | Value |
+-------------------------------------+----------------+
| innodb_buffer_pool_chunk_size | 134217728 |
| innodb_buffer_pool_dump_at_shutdown | ON |
| innodb_buffer_pool_dump_now | OFF |
| innodb_buffer_pool_dump_pct | 25 |
| innodb_buffer_pool_filename | ib_buffer_pool |
| innodb_buffer_pool_instances | 8 |
| innodb_buffer_pool_load_abort | OFF |
| innodb_buffer_pool_load_at_startup | ON |
| innodb_buffer_pool_load_now | OFF |
| innodb_buffer_pool_size | 120259084288 |
+-------------------------------------+----------------+