4.2.4 Restoring a Database

To restore a MySQL instance from a backup to a database server:

Shut down the database server.
Delete all files inside the server's data directory. Also delete all files inside the directories specified by the --innodb_data_home_dir, --innodb_log_group_home_dir, and --innodb_undo_directory options for restore, if the directories are different from the data directory.
Use, for example, the copy-back-and-apply-log command, which converts the raw backup into a prepared backup by updating it to a consistent state, and then copies the tables, indexes, metadata, and any other required files onto a target server. For the various options that you can specify for this operation, see Section 19.3, “Restore Operations”.

In the example below, the single-file backup created in the example given in Section 4.2.2, “Backing Up an Entire MySQL Instance” is restored using the copy-back-and-apply-log command. The following options are used:

--datadir supplies the location of the data directory for restoring the data. You must specify this option for any restore operation, either at the command line or in a defaults file.
--backup-image provides the path of the single-file backup.
--backup-dir provides the location of an empty folder to store some temporary files created during the restore procedure.

$ mysqlbackup --datadir=/home/admin/bin/mysql-commercial-8.0.16/datadir \
  --backup-image=/home/mysqlbackup/backups/my.mbi --backup-dir=/home/mysqlbackup/backup-tmp \
    copy-back-and-apply-log
MySQL Enterprise Backup  Ver 8.0.16-commercial for linux-glibc2.12 on x86_64 (MySQL Enterprise - Commercial)
Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Starting with following command line ...
 mysqlbackup --datadir=/home/admin/bin/mysql-commercial-8.0.16/datadir 
      --backup-image=/home/mysqlbackup/backups/my.mbi 
      --backup-dir=/home/mysqlbackup/backup-tmp copy-back-and-apply-log 

IMPORTANT: Please check that mysqlbackup run completes successfully.
           At the end of a successful 'copy-back-and-apply-log' run mysqlbackup
           prints "mysqlbackup completed OK!".

190402 16:56:37 MAIN    INFO: Starting to log actions.
190402 16:56:37 MAIN    INFO: Backup directory exists: '/home/mysqlbackup/backup-tmp'
190402 16:56:37 MAIN    INFO: Backup Image MEB version string: 8.0.16 [2019-03-26  18:51:33]
190402 16:56:37 MAIN    INFO: MySQL server version is '8.0.16'
190402 16:56:37 MAIN WARNING: If you restore to a server of a different version, the innodb_data_file_path parameter might have a different default. In that case you need to add 'innodb_data_file_path=ibdata1:12M:autoextend' to the target server configuration.
190402 16:56:37 MAIN WARNING: If you restore to a server of a different version, the innodb_log_files_in_group parameter might have a different default. In that case you need to add 'innodb_log_files_in_group=2' to the target server configuration.
190402 16:56:37 MAIN WARNING: If you restore to a server of a different version, the innodb_log_file_size parameter might have a different default. In that case you need to add 'innodb_log_file_size=50331648' to the target server configuration.
190402 16:56:37 MAIN    INFO: Server is not a community server.
190402 16:56:37 MAIN    INFO: KEF source path:'/home/mysqlbackup/backup-tmp/meta/keyring_kef'
190402 16:56:37 MAIN    INFO: KEF target path:'/home/admin/bin/mysql-commercial-8.0.16/datadir/keyring_kef'
190402 16:56:37 MAIN    INFO: TDE Keyring service initialized.
190402 16:56:37 MAIN    INFO: MEB logfile created at /home/mysqlbackup/backup-tmp/meta/MEB_2019-04-02.16-56-37_copy_back_img_to_datadir.log

--------------------------------------------------------------------
                       Server Repository Options:
--------------------------------------------------------------------
  datadir                        = /home/admin/bin/mysql-commercial-8.0.16/datadir
  innodb_data_home_dir           = /home/admin/bin/mysql-commercial-8.0.16/datadir
  innodb_data_file_path          = ibdata1:12M:autoextend
  innodb_log_group_home_dir      = /home/admin/bin/mysql-commercial-8.0.16/datadir
  innodb_log_files_in_group      = 2
  innodb_log_file_size           = 50331648
  innodb_undo_directory          = /home/admin/bin/mysql-commercial-8.0.16/datadir
  innodb_undo_tablespaces        = 2
  innodb_buffer_pool_filename    = ib_buffer_pool
  innodb_page_size               = Null
  innodb_checksum_algorithm      = crc32

--------------------------------------------------------------------
                       Backup Config Options:
--------------------------------------------------------------------
  datadir                        = /home/mysqlbackup/backup-tmp/datadir
  innodb_data_home_dir           = /home/mysqlbackup/backup-tmp/datadir
  innodb_data_file_path          = ibdata1:12M:autoextend
  innodb_log_group_home_dir      = /home/mysqlbackup/backup-tmp/datadir
  innodb_log_files_in_group      = 2
  innodb_log_file_size           = 50331648
  innodb_undo_directory          = /home/mysqlbackup/backup-tmp/datadir
  innodb_undo_tablespaces        = 2
  innodb_buffer_pool_filename    = ib_buffer_pool
  innodb_page_size               = 16384
  innodb_checksum_algorithm      = crc32

190402 16:56:37 MAIN    INFO: Creating 14 buffers each of size 16777216.
190402 16:56:37 MAIN    INFO: Copy-back-and-apply-log operation starts with following threads
		1 read-threads    6 process-threads    1 write-threads
190402 16:56:37 PCR1    INFO: Copying database directory: meta
190402 16:56:37 RDR1    INFO: Copying ibdata1.
190402 16:56:37 RDR1    INFO: Copying undo_002.
190402 16:56:37 RDR1    INFO: Copying undo_001.
190402 16:56:37 RDR1    INFO: Copying sys/sys_config.ibd.
190402 16:56:37 RDR1    INFO: Copying pets/cats.ibd.
190402 16:56:37 RDR1    INFO: Copying mysql/backup_history.ibd.
190402 16:56:37 RDR1    INFO: Copying mysql.ibd.
190402 16:56:37 RDR1    INFO: Copying binlog.000001.
190402 16:56:37 RDR1    INFO: Copying binlog.000002.
190402 16:56:37 RDR1    INFO: Copying binlog.000003.
190402 16:56:37 PCR3    INFO: Copying database directory: mysql
190402 16:56:37 PCR3    INFO: Copying database directory: performance_schema
190402 16:56:37 PCR3    INFO: Copying database directory: pets
190402 16:56:37 PCR3    INFO: Copying database directory: sys
190402 16:56:37 RDR1    INFO: Copying binlog.000004.
190402 16:56:37 MAIN    INFO: Total files as specified in image: 138
190402 16:56:37 MAIN    INFO: MySQL server version is '8.0.16-commercial'
190402 16:56:37 MAIN    INFO: Restoring ...8.0.16-commercial version
190402 16:56:37 MAIN    INFO: Copy-back operation completed successfully.
190402 16:56:37 MAIN    INFO: Source Image Path = /home/mysqlbackup/backups/my.mbi


190402 16:56:37 MAIN    INFO: MySQL server version is '8.0.16-commercial'
190402 16:56:37 MAIN    INFO: Restoring ...8.0.16-commercial version
190402 16:56:37 MAIN    INFO: Creating 14 buffers each of size 65536.
190402 16:56:37 MAIN    INFO: Apply-log operation starts with following threads
		1 read-threads    1 process-threads    6 apply-threads
190402 16:56:37 MAIN    INFO: Using up to 100 MB of memory.
190402 16:56:37 MAIN    INFO: ibbackup_logfile's creation parameters:
          start lsn 19841024, end lsn 19841405,
          start checkpoint 19841405.
190402 16:56:37 MAIN    INFO: Loading the space id : 0, space name : /home/admin/bin/mysql-commercial-8.0.16/datadir/ibdata1.
190402 16:56:37 MAIN    INFO: Apply log: Loading the undo space id : 4294967278, space name : /home/admin/bin/mysql-commercial-8.0.16/datadir/undo_002.
190402 16:56:37 MAIN    INFO: Apply log: Loading the undo space id : 4294967279, space name : /home/admin/bin/mysql-commercial-8.0.16/datadir/undo_001.
190402 16:56:37 MAIN    INFO: Loading the space id : 3, space name : /home/admin/bin/mysql-commercial-8.0.16/datadir/mysql/backup_history.ibd.
190402 16:56:37 MAIN    INFO: Loading the space id : 2, space name : /home/admin/bin/mysql-commercial-8.0.16/datadir/pets/cats.ibd.
190402 16:56:37 MAIN    INFO: Loading the space id : 1, space name : /home/admin/bin/mysql-commercial-8.0.16/datadir/sys/sys_config.ibd.
190402 16:56:37 MAIN    INFO: Loading the space id : 4294967294, space name : /home/admin/bin/mysql-commercial-8.0.16/datadir/mysql.ibd.
190402 16:56:37 PCR1    INFO: Starting to parse redo log at lsn = 19841394, whereas checkpoint_lsn = 19841405.
190402 16:56:37 PCR1    INFO: Doing recovery: scanned up to log sequence number 19841405.
190402 16:56:37 PCR1    INFO: Starting to apply a batch of log records to the database....
InnoDB: Progress in percent: 
190402 16:56:37 PCR1    INFO: Updating last checkpoint to 19841405 in redo log/
190402 16:56:37 PCR1    INFO: Setting log file size to 50331648
190402 16:56:37 PCR1    INFO: Setting log file size to 50331648
190402 16:56:37 PCR1    INFO: Log file header:
	 format = 3 
	 pad1 = 0 
	 start lsn = 19841024 
	 checkpoint lsn = 19841405 
	 checksum = 2051460933
	 creator = MEB 8.0.16
190402 16:56:37 PCR1    INFO: We were able to parse ibbackup_logfile up to
          lsn 19841405.
190402 16:56:37 PCR1    INFO: Last MySQL binlog file position 0 379, file name binlog.000004
190402 16:56:37 PCR1    INFO: The first data file is '/home/admin/bin/mysql-commercial-8.0.16/datadir/ibdata1'
                              and the new created log files are at '/home/admin/bin/mysql-commercial-8.0.16/datadir'
190402 16:56:37 MAIN    INFO: No Keyring file to process.
190402 16:56:37 MAIN    INFO: Apply-log operation completed successfully.
190402 16:56:37 MAIN    INFO: Full Backup has been restored successfully.

mysqlbackup completed OK! with 3 warnings

Now the original database directory is restored from the backup.

Starting the Restored Server. When the following InnoDB settings are different on the backed-up and the restored server, it is important to configure the restored server with the settings from the backed up server (otherwise, your restored server might not start):

If you are not sure about those settings for your backed-up server, they were actually stored in the backup-my.cnf file during the backup—you can find the file either in the temporary directory you specified with --backup-dir when you restored the single-image backup, or in a backup directory you could create by unpacking the backup image using the extract command. If the values of these options differ from those on the target server, add them to the configuration file you are using to start the target server afterwards; alternatively, you can also supply them as command line options to mysqld.

Depending on how you are going to start the restored server, you might need to adjust the ownership of the restored data directory. For example, if the server is going to be started by the user mysql, use the following command to change the owner attribute of the data directory and the files under it to the mysql user, and the group attribute to the mysql group.

$ chown -R mysql:mysql /path/to/datadir

You are now ready to start the restored database server. For more discussions on how to perform different kinds of restores, see Section 5.1, “Performing a Restore Operation”.