5.1.7 Advanced: Preparing and Restoring a Directory Backup

A directory backup, just like a single-file backup, can be prepared and restored using the copy-back-and-apply-log command as explained at the beginning of Section 5.1, “Performing a Restore Operation”.

Example 5.14 Restoring a Backup Directory using copy-back-and-apply-log

mysqlbackup --defaults-file=/usr/local/mysql/my.cnf \
  --backup-dir=/export/backups/full \
    copy-back-and-apply-log

However, two alternatives exist for directory backups:

Perform the apply log operation on the raw backup right after the backup, or anytime before restore, using the apply-log command. You can run this step on the same database server where you did the backup, or transfer the raw backup files to a different system first, to limit the CPU and storage overhead on the database server. Here are some examples of doing that, on different kinds of directory backups:
Example 5.15 Applying the Log to a Backup
This example runs mysqlbackup to roll forward the data files so that the data is ready to be restored:
```
mysqlbackup --backup-dir=/export/backups/2011-06-21__8-36-58 apply-log
```
That command creates InnoDB log files (ib_logfile*) within the backup directory and applies log records to the InnoDB data files (ibdata* and *.ibd).
Example 5.16 Applying the Log to a Compressed Backup
If the backup is compressed, as in Section 4.3.4, “Making a Compressed Backup”, specify the --uncompress option to mysqlbackup when applying the log to the backup:
```
mysqlbackup --backup-dir=/export/backups/compressed --uncompress apply-log
```
Note
Since the apply log operation does not modify any of the original files in the backup, nothing is lost if the operation fails for some reason (for example, insufficient disk space). After fixing the problem, you can safely retry apply-log and by specifying the --force option, which allows the data and log files created by the failed apply log operation to be overwritten.
For backups that are non-incremental, you can combine the initial backup and the apply-log steps using the backup-and-apply-log command.

After the backup has been prepared, you can now restore it using the copy-back command:

mysqlbackup --defaults-file=/usr/local/mysql/my.cnf \
  --backup-dir=/export/backups/full \
    copy-back