manual.texi:

# You can write your other MySQL server options here

# ...

#

innodb_data_file_path = ibdata1:2000M;ibdata2:2000M

innodb_data_home_dir = c:\ibdata

set-variable = innodb_mirrored_log_groups=1

#                                            Data files must be able to

#                                            hold your data and indexes

innodb_data_file_path = ibdata1:2000M;ibdata2:2000M

#                                            Set buffer pool size to 50 - 80 %

#                                            of your computer's memory

set-variable = innodb_buffer_pool_size=70M

set-variable = innodb_additional_mem_pool_size=10M

innodb_log_group_home_dir = c:\iblogs

#                                            .._log_arch_dir must be the same

#                                            as .._log_group_home_dir

innodb_log_arch_dir = c:\iblogs

innodb_log_archive=0

set-variable = innodb_log_files_in_group=3

set-variable = innodb_log_file_size=30M

#                                            Set the log file size to about

#                                            15 % of the buffer pool size

set-variable = innodb_log_file_size=10M

set-variable = innodb_log_buffer_size=8M

#                                            Set ..flush_log_at_trx_commit to

#                                            0 if you can afford losing

#                                            a few last transactions 

innodb_flush_log_at_trx_commit=1

#.._arch_dir must be the same as .._log_group_home_dir

innodb_log_arch_dir = c:\iblogs

innodb_log_archive=0

set-variable = innodb_buffer_pool_size=70M

set-variable = innodb_additional_mem_pool_size=10M

set-variable = innodb_file_io_threads=4

set-variable = innodb_lock_wait_timeout=50

@end example

Note that some operating systems

restrict file size to < 2G.

The total size of data files has

Note that data files must be < 4G, and < 2G on

some file systems! The total size of data files has

to be >= 10 MB.

InnoDB does not create directories:

you have to create them yourself.

Check that the MySQL server

has the rights to create files in the directories you specify.

When you the first time create an InnoDB database, it

is best that you start the MySQL server from the command

prompt. Then InnoDB will print the information about the

database creation to the screen, and you see what is

happening. See below in section 3 what the printout

should look like.

For example, in Windows you can start @file{mysqld-max.exe} with:

@example

your-path-to-mysqld>mysqld-max --standalone --console

@end example

Suppose you have a Linux machine with 512 MB RAM and

Suppose you have a Linux computer with 512 MB RAM and

three 20 GB hard disks (at directory paths @file{/},

@file{/dr2} and @file{/dr3}).

Below is an example of possible configuration parameters in @file{my.cnf} for

# You can write your other MySQL server options here

# ...

#

innodb_data_file_path = ibdata/ibdata1:2000M;dr2/ibdata/ibdata2:2000M

innodb_data_home_dir = /

set-variable = innodb_mirrored_log_groups=1

innodb_log_group_home_dir = /dr3

#                                            Data files must be able to

#                                            hold your data and indexes

innodb_data_file_path = ibdata/ibdata1:2000M;dr2/ibdata/ibdata2:2000M

#                                            Set buffer pool size to 50 - 80 %

#                                            of your computer's memory

set-variable = innodb_buffer_pool_size=350M

set-variable = innodb_additional_mem_pool_size=20M

innodb_log_group_home_dir = /dr3/iblogs

#                                            .._log_arch_dir must be the same

#                                            as .._log_group_home_dir

innodb_log_arch_dir = /dr3/iblogs

innodb_log_archive=0

set-variable = innodb_log_files_in_group=3

#                                            Set the log file size to about

#                                            15 % of the buffer pool size

set-variable = innodb_log_file_size=50M

set-variable = innodb_log_buffer_size=8M

#                                            Set ..flush_log_at_trx_commit to

#                                            0 if you can afford losing

#                                            a few last transactions 

innodb_flush_log_at_trx_commit=1

#.._arch_dir must be the same as .._log_group_home_dir

innodb_log_arch_dir = /dr3/iblogs

innodb_log_archive=0

set-variable = innodb_buffer_pool_size=350M

set-variable = innodb_additional_mem_pool_size=20M

set-variable = innodb_file_io_threads=4

set-variable = innodb_lock_wait_timeout=50

#innodb_flush_method=fdatasync

#innodb_fast_shutdown=1

#set-variable = innodb_thread_concurrency=5

@end example

Note that we have placed the two data files on different disks.

on the same physical disk. Putting log files on a different disk from

data is very often beneficial for performance.

The combined size of the log files MUST be < 4G in a 32-bit computer,

and to make recovery reasonably fast you should keep the combined size

smaller than the buffer pool size.

The meanings of the configuration parameters are the following:

@multitable @columnfractions .30 .70

circular fashion. Value 3 is recommended here.

@item @code{innodb_log_file_size} @tab 

Size of each log file in a log group in megabytes. Sensible values range

from 1M to the size of the buffer pool specified below. The bigger the

value, the less checkpoint flush activity is needed in the buffer pool,

from 1M to 1/nth of the size of the buffer pool specified below,

where n is the number of log files in the group. The

bigger the value,

the less checkpoint flush activity is needed in the buffer pool,

saving disk i/o. But bigger log files also mean that recovery will be

slower in case of a crash. The combined size of log files must

be < 4 GB on 32-bit computers.