These options specify various parameters related to the layout of the backup directory.
The --backup-dir
option is the only one from
this group that you typically specify. Values for all the
backup_innodb_*
options can be derived
automatically from the corresponding configuration options
without the backup_
prefix (see descriptions
for individual options below). Those options need to be
specified only if, during a backup, the user wants to specify
particular values for those options that are to be used during
restorations of the backup. Values specified by
backup_innodb_*
options are stored in the
backup_my.cnf
file, to be used during
future restorations.
When a database connection is available during a backup, those
backup_innodb_*
options are ignored, with
their values overridden by the corresponding values retrieved
from the database connection. .
These options are used only with the following operations:
Backup creation operations:
backup
,backup-and-apply-log
,backup-to-image
.Restore operations:
copy-back
,copy-back-and-apply-log
.
The following parameters describe the layout of files in the backup directory:
Same as
--backup-dir
. The directory under which to store the backup data. This is a crucial parameter required for most kinds of backup operations. It cannot be a subdirectory of the directory specified by--datadir
. An additional level of subdirectory is created when the--with-timestamp
option is also specified.Also, when restoring a single-file backup with
copy-back-and-apply-log
,--backup-dir
is used for supplying the location of a folder that will be used for storing temporary files produced during the restoration process.backup_innodb_data_home_dir
=PATH
Specifies the directory where backup InnoDB data files live. Usually same as
backup-dir
, but can be different.This parameter together with
backup_innodb_data_file_path
determines where the InnoDB data files (such asibdata1
,ibdata2
, ...) are stored inside the backup directory structure.This parameter is applicable only for backup operations, not restore.
For the backup operations (such as
backup
,backup-and-apply-log
,backup-to-image
), the value of the backup destination directory is derived as follows:If
backup_innodb_data_home_dir
is not specified, it inherits the value ofbackup-dir
.If
backup_innodb_data_home_dir
is a relative path, that path is located relative to (that is, underneath) thebackup-dir
value.An
backup_innodb_data_home_dir
of""
refers to the/
root directory.If
backup_innodb_data_home_dir
is an absolute path, its value is used as-is.
To make it easy to relocate the backup directory and avoid editing the
backup-my.cnf
file, the backup operation writes this value intobackup-my.cnf
only if it is different than thebackup-dir
value, and using a relative path if possible.For
backup-to-image
operations, the final value of thebackup_innodb_data_home_dir
option must be a relative path, so that the single-file backup is machine-independent.backup_innodb_data_file_path
=VALUE
Specifies InnoDB data file names and sizes. Examples:
ibdata1:32M;ibdata2:32M:autoextend /abs/path/ibdata1:32M:autoextend innodb-dir/ibdata1:32M:autoextend
This parameter together with
backup_innodb_data_home_dir
determines where the InnoDB data files (such asibdata1
,ibdata2
, ...) live in the backup repository.Within the backup directory, any data files specified with relative paths are located relative to the
backup_dir
path. Any data files specified with absolute paths are placed inside thebackup_innodb_data_home
directory.When the parameter is not specified, it inherits the value from the value of the
innodb_data_file_path
option. If both source and destination attempt to use an absolute path that resolve to the same files, the backup is cancelled.To specify absolute paths for InnoDB datafiles in backup, you must also set the
backup_innodb_data_home
option to""
.backup_innodb_log_group_home_dir
=PATH
Specifies where backup InnoDB logs live. Usually the same as
backup-dir
, but can be different.The names of the log files are fixed and not reconfigurable.
This parameter is applicable only for backup operations (not restore).
The backup operation uses this value and writes it as
innodb_log_group_home_dir=
invalue
backup-my.cnf
.For
copy-back
andapply-log
operations,innodb_log_group_home_dir
inbackup-my.cnf
is treated in a way that is compatible with how it was created.backup_innodb_log_files_in_group
=N
Specifies the number of InnoDB log files in backup before being rotated. Example: 5.
Usually same as
innodb_log_files_in_group
, but can be different.The value for this parameter is derived as:
Specified
backup_innodb_log_files_in_group
value from command line or configuration file.Else
innodb_log_files_in_group
value from the database connection, if available.Else the
innodb_log_files_in_group
value from the command line or configuration file.
backup_innodb_log_file_size
=SIZE
Specifies maximum single InnoDB log file size in backup before switching to next log file. Example: 20M.
Usually the same as
innodb_log_file_size
, but can be different.The value for this parameter is derived as:
Specified
backup_innodb_log_file_size
value from command line or configuration file.Else
innodb_log_file_size
value from database connection, if available.Else specified
innodb_log_file_size
value from command line or configuration file.
The page size for all InnoDB tablespaces in a MySQL instance. The page size must be the same value as in MySQL instance. By default, it assumes the innodb page size in server.
backup_innodb_checksum_algorithm
=NAME
The name of the checksum algorithm used for validating InnoDB tablespaces. Default is 'innodb'.
backup_innodb_undo_directory
=PATH
The relative or absolute directory path where InnoDB creates separate tablespaces for the undo logs. Typically used to place those logs on a different storage device.
backup_innodb_undo_logs
=NUMBER
Number of rollback segments in the system tablespace that InnoDB uses within a transaction. This setting is appropriate for tuning performance if you observe mutex contention related to the undo logs.
backup_innodb_undo_tablespaces
=NUMBER
The number of tablespace files that the undo logs are divided between, when you use a non-zero innodb_undo_logs setting. By default, all the undo logs are part of the system tablespace and the system tablespace will always contain one undo tablespace in addition to those configured by innodb_undo_tablespaces.
Creates a subdirectory underneath the backup directory, with a name formed from the timestamp of the backup operation. Useful to maintain a single backup directory containing many backup snapshots.
Default: no timestamped subdirectory is created. To reuse the same backup directory for a new backup, either remove the previous backup files manually or specify the
--force
option to overwrite them.