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MySQL Enterprise Backup 8.4 User's Guide
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4.3.1 Making a Single-File Backup

To avoid having a large number of backup files to keep track, store, and transport, mysqlbackup conveniently creates backups in a single-file format. It can also pack an existing backup directory into a single file, unpack the single file back to a backup directory, list the contents of a single-file backup, verify the contents of a single-file backup against embedded checksums, or extract a single file into a directory tree. For the syntax of the relevant mysqlbackup options, see Section 20.9, “Single-File Backup Options”.

Advanced: While mysqlbackup can also create a directory backup (see description for the backup command for details) instead of a single-file backup, the single-file format is preferable in most cases: a single-file backup is easier to handle and store, and certain functions of mysqlbackup are not supported for directory backups—for example, backup to cloud and backup to tape using the System Backup to Tape (SBT) API. Throughout the manual, directory backup is mostly treated as an advanced topic, and information and examples for directory backups are marked with the Advanced tag, like this paragraph.

Because the single-file backup can be streamed or piped to another process such as a tape backup or a command, you can use the technique to put the backup onto another storage device or server and avoid significant storage overhead on the original database server.

To create a single-file backup, use the backup-to-image command. The following examples illustrate how to perform a single-file backup and other related operations.

Example 4.1 Single-File Backup to Absolute Path

This command creates a single backup image on the given absolute path. It still requires --backup-dir, which is used to hold temporary output, status, and metadata files.

mysqlbackup --defaults-file=/home/dbadmin/my.cnf --backup-image=/backups/sales.mbi --backup-dir=/backup-tmp backup-to-image

Example 4.2 Single-File Backup to Relative Path

When a relative path instead of an absolute path was supplied with the --backup-image option, the path is taken to be relative to the backup directory. Therefore, in this example, the resulting single-file backup is created as /backups/sales.mbi.

mysqlbackup --defaults-file=/home/dbadmin/my.cnf --backup-image=sales.mbi --backup-dir=/backups backup-to-image

Example 4.3 Single-File Backup to Standard Output

The following command dumps the backup output to standard output. Again, the folder specified with the --backup-dir option is used as a temporary directory.

mysqlbackup --defaults-file=/home/dbadmin/my.cnf --backup-dir=/backups --backup-image=- backup-to-image > /backup/mybackup.mbi

Example 4.4 Convert Existing Backup Directory to Single Image

The backup-dir directory is bundled into the /backup/my.mbi file.

mysqlbackup --backup-image=/backup/my.mbi --backup-dir=/var/mysql/backup backup-dir-to-image

Example 4.5 Extract Existing Image to Backup Directory

The image contents are unpacked into backup-dir.

mysqlbackup --backup-dir=/var/backup --backup-image=/backup/my.mbi image-to-backup-dir

Example 4.6 List Single-File Backup Contents

The image contents are listed, with each line indicating a file or directory entry.

mysqlbackup --backup-image=/backup/my.mbi list-image

Example 4.7 Validate a Single-File Backup

The following command verifies that the single-file backup is not corrupted, truncated, or damaged by validating the checksum value for each data page in the backup.

mysqlbackup --backup-image=/logs/fullimage.mi  validate

Example 4.8 Extract Single-File Backup into Current Directory

The following command extracts all contents from a single-file backup into the current working directory.

mysqlbackup --backup-image=/var/my.mbi extract

Example 4.9 Extract Single-File Backup into a Backup Directory

This command extracts all contents of a single-file backup into the directory specified with the --backup-dir option.

mysqlbackup --backup-image=/var/my.mbi --backup-dir=/var/backup extract

Example 4.10 Selective Extract of Single File

The following command extracts the single file meta/comments.txt from the backup image my.mbi into the local path./meta/comments.txt.

mysqlbackup --backup-image=/var/my.mbi \
  --src-entry=meta/comments.txt extract

The following command extracts the meta/comments.txt file from the backup image my.mbi into a specified path /tmp/mycomments.txt by using the --dst-entry option.

mysqlbackup --backup-image=/var/my.mbi \
  --src-entry=meta/comments.txt \
  --dst-entry=/tmp/mycomments.txt extract

The following command dumps the contents of meta/comments.txt (which is inside the single-file backup my.mbi) to standard output.

mysqlbackup --backup-image=/var/my.mbi --src-entry=meta/comments.txt --dst-entry=- extract

Example 4.11 Selective Extract of Single Directory

The following command extracts a single directory meta from the backup image my.mbi into a local file system path ./meta. All contents in the meta directory are extracted, including any subdirectories. (Notice the slash (/) at the end of the value meta/ for --src-entry, without which all files or folders containing the string meta in their pathnames will be extracted.)

mysqlbackup --backup-image=/backup/my.mbi --src-entry=meta/ extract

Example 4.12 Dealing with Absolute Path Names

Since absolute pathnames are extracted to the same paths in local system, it could be a problem if you do not have write permission for that path. You can remap absolute paths as follows:

mysqlbackup --backup-image=/backup/my.mbi --src-entry=/ --dst-entry=/myroot extract
mysqlbackup --backup-image=/backup/my.mbi --src-entry=. extract

The first command extracts all absolute paths to /myroot directory in the local system. The second command extracts all relative paths to the current directory.