Questions[innodb-barracuda](server)

I have an innodb on a Ubuntu 10.10 server running on an ESXi platform. I have dedicated 8 CPUs, 32 Gigs of ram, and files stored in a Raid 5 HP SAN of SAS 10k rpm disks. I'm expecting FAST queries! However: select count('x') takes 45 seconds for 75 million rows! So, I dug into tuning this beast:

1) Some of my settings cause mysql to bomb out with "Unknown variable" errors. These are:

innodb_file_format = barracuda
innodb_read_io_threads = 6
innodb_write_io_threads = 6
innodb_io_capacity = 1000

2) The rest of my settings that do not crash mysql but are probably not optimized..

skip_name_resolve
default_storage_engine = InnoDB
innodb_file_per_table = 1
innodb_buffer_pool_size = 24G
innodb_log_files_size = 1G
innodb_log_buffer_size = 8M
innodb_flush_method = O_DIRECT
innodb_flush_log_at_trx_comit = 1

key_buffer = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 32
query_cache_limit = 1M
query_cache_size = 0

Is there any additional tuning that you would recommend on these settings? Any additional settings that I am missing?

Thanks for the support!

In new MySQL versions Barracuda file format was introduced. So I havew a few questions:

• Is it working only with file_per_table option?
• How to switch existing system to it (preferably the whole tablespace) other than by reimporting everything from mysqldump backup on empty server?