This section lists some common questions about MySQL Enterprise Backup, with answers and pointers to further information.
Questions
A.1: What versions of the MySQL server does MySQL Enterprise Backup 4.1 support?
A.2: What is the big
ibdata
file that is in all the backups?A.3: Can I back up non-InnoDB data with MySQL Enterprise Backup?
A.4: What happens if the apply-log or apply-incremental-backup step is interrupted?
A.5: Why is the option
--defaults-file
not recognized?A.6: Can I back up a database on one OS platform and restore it on another one using MySQL Enterprise Backup?
A.7: What if I have included the binary log or relay log in my backup but do not want to restore it?
A.8: What would happen if I start a server directly using a raw directory backup, without running either the copy-back or the apply-log operation?
Questions and Answers
A.1: What versions of the MySQL server does MySQL Enterprise Backup 4.1 support?
See Section C.3, “Compatibility with MySQL Versions” for details of compatibility between different releases of MySQL Enterprise Backup and MySQL Server.
A.2:
What is the big ibdata
file that is in
all the backups?
You might find your backup data taking more space than
expected because of a large file with a name such as
ibdata1
. This file represents the InnoDB
system
tablespace, which grows but never shrinks as a database
operates, and is included in every full and incremental
backup. To reduce the space taken up by this file in your
backup data:
After doing a full backup, do a succession of incremental backups, which take up less space. The
ibdata1
file in the incremental backups is typically much smaller, containing only the portions of the system tablespace that changed since the full backup.Set the configuration option
innodb_file_per_table=1
before creating your biggest or most active InnoDB tables. Those tables are split off from the system tablespaces into separate.ibd
files; the tables can then be individually included or excluded from backups, and disk space is freed when the tables are dropped or truncated.If your system tablespace is very large because you created a high volume of InnoDB data before turning on the
innodb_file_per_table
setting, you might use mysqldump to create a dump of your entire server instance, then turn oninnodb_file_per_table
before re-creating the database, so that all the table data is kept outside the system tablespace.
A.3: Can I back up non-InnoDB data with MySQL Enterprise Backup?
While MySQL Enterprise Backup can back up non-InnoDB data
(like MYISAM tables), the MySQL server to be backed up must
support InnoDB (i.e., the backup process will fail if the
server was started up with the
--innodb=OFF
or
--skip-innodb
option), and the server must contain at least one InnoDB
table.
A.4: What happens if the apply-log or apply-incremental-backup step is interrupted?
If mysqlbackup is interrupted during the
apply-log
or
apply-incremental-backup
stage,
the backup data is OK. The file operations performed by those
options can be performed multiple times without harming the
consistency of the backup data. Just run the same
mysqlbackup command again, and when it
completes successfully, all the necessary changes are present
in the backup data.
A.5:
Why is the option --defaults-file
not
recognized?
When you specify the
--defaults-file
option, it
must be the first option going after
mysqlbackup. Otherwise, the error message
makes it look as if the option name is not recognized.
A.6: Can I back up a database on one OS platform and restore it on another one using MySQL Enterprise Backup?
See Section C.2, “Cross-Platform Compatibility” for details.
A.7: What if I have included the binary log or relay log in my backup but do not want to restore it?
If you want to skip the restore of the binary log, relay log,
or both during a restore, use the
--skip-binlog
option, the
--skip-relaylog
option, or both
with your copy-back
or
copy-back-and-apply-log
command.
A.8: What would happen if I start a server directly using a raw directory backup, without running either the copy-back or the apply-log operation?
This should never be attempted. Not only would the server crash, but the backup would likely get corrupted and become unusable. This is because the directory backup contains metadata created by mysqlbackup that the MySQL server would not understand; also, the raw backup might be inconsistent and need to be brought up-to-date by an apply-log operation, so that changes made to the database during the backup process can be applied.