Perform secondary backup |V2.2.77|OceanBase Database| docs|Distributed Database

Perform secondary backup

Last Updated：2023-08-18 09:26:34 Updated

Secondary backup of data backups

The secondary backup of data backups is performed by transferring the data backups saved at the source backup location to the destination backup location.

Run the following commands to perform secondary backup on data backups:

obclient> ALTER SYSTEM BACKUP BACKUPSET ALL;

obclient> ALTER SYSTEM BACKUP BACKUPSET N;

In the commands:

ALL indicates the backup set of all data backups.
N indicates the backup_set_id of backups to be included in the secondary backup.

Assume that five backup sets exist with backup_set_id of 1, 2, 3, 4, and 5, and that 1, 2, and 4 are full backups whereas 3 and 5 are incremental backups. The following examples perform secondary backup on them.

Perform secondary backup on all current backup sets.
```
obclient> ALTER SYSTEM BACKUP BACKUPSET ALL;
```
Perform secondary backup on the backup set whose backup_set_id is 3.
```
obclient> ALTER SYSTEM BACKUP BACKUPSET 3;
```
If one backup set is dependent on another, and you have performed secondary backup by specifying the backup_set_id of the referenced backup set first, the system prompts an execution error when you try to perform secondary backup by specifying the backup_set_id of the dependent backup set.

For the example backup sets, if you execute ALTER SYSTEM BACKUP BACKUPSET 3; first and then ALTER SYSTEM BACKUP BACKUPSET 1;, the execution will fail.

Secondary backup of non-split log backups

The secondary backup of non-split log backups is performed by transferring the logs saved at the source backup location to the destination backup location.

Configure the destination for secondary backup.

Before you perform secondary backup, you must specify the destination for secondary backup by setting backup_backup_dest to an OSS or NFS storage. This is similar to setting backup_dest. For more information about setting backup_dest, see Backup by using commands.

Example:

In the command, xxx indicates the destination for secondary backup.
```
obclient> ALTER SYSTEM SET backup_backup_dest='xxx';
```
Set the interval for the worker thread of secondary backup.

In the backup_backup_dest_option configuration item, log_archive_checkpoint_interval specifies the interval for performing secondary backup on log backups. For more information about backup_backup_dest_option, see the "backup_backup_dest_option" topic in Reference Guide (MySQL Mode) or Reference Guide (Oracle Mode).

Example:
```
obclient> ALTER SYSTEM SET backup_backup_dest_option = 'log_archive_checkpoint_interval='30s';
```
Start the worker thread of secondary backup for log backups.
```
obclient> ALTER SYSTEM START BACKUP ARCHIVELOG;
```
Note

After the worker thread is started, you can execute the ALTER SYSTEM STOP BACKUP ARCHIVELOG; statement to stop it.

Secondary backup of split log backups

In physical backup and recovery, the content of the backup directory can be split. You can resolve the problem of insufficient capacity on the backup storage media by performing secondary backup on the split content.

Preparations

To split the content of the backup directory, you need to set the options for each backup destination first. That is, backup_dest_option and backup_backup_dest_option need to be set.
- Set backup_dest_option.
  
  backup_dest_option specifies parameters related to backup. For more information about backup_dest_option, see the "backup_dest_option" topic in Reference Guide (MySQL Mode) or Reference Guide (Oracle Mode).
  
  Example:
```
obclient> ALTER SYSTEM SET backup_dest_option='log_archive_checkpoint_interval=2m&recovery_window=7d&auto_delete_obsolete_backup=true&log_archive_piece_switch_interval=1d&backup_copies=2';
```
  In this example, the log archiving interval is 5s, and a backup piece is split from the log backups every day. This backup piece is retained for seven days, and then automatically cleared. By setting backup_copies to 2, the original backup is only recycled after its secondary backup is performed.
- Set backup_backup_dest_option.
  
  backup_backup_dest_option specifies parameters related to secondary backup. For more information about backup_backup_dest_option, see the "backup_backup_dest_option" topic in Reference Guide (MySQL Mode) or Reference Guide (Oracle Mode).
  
  Example:
```
obclient> ALTER SYSTEM SET backup_backup_dest_option='log_archive_checkpoint_interval=2m&recovery_window=14d&auto_delete_obsolete_backup=true';
```
  In this example, a secondary backup is performed on the log backups every 2 minutes, and these secondary backups expire in fourteen days.
Start physical backup. For more information about physical backup, see Backup by using commands.

Perform secondary backup on a single backup directory

If you need to perform secondary backup on a single backup directory, you can specify a single backup set or backup piece. To archive the secondary backup to a destination different from the one specified in backup_backup_dest, you can specify another destination in the secondary backup command.

Run the following commands to perform secondary backup on a single backup directory:

obclient> ALTER SYSTEM BACKUP BACKUPSET [=N] [backup_backup_dest = uri];

obclient> ALTER SYSTEM BACKUP BACKUPPIECE [=N] [backup_backup_dest = uri];

In the commands:

N indicates the backup_set_id or piece_id to be included in the secondary backup.
uri indicates the destination for archiving the secondary backup data.

Examples:

Save a secondary backup for the backup whose backup_set_id is 1 to the file:///data/backup_backup_nfs directory.
```
obclient> ALTER SYSTEM BACKUP BACKUPSET 1 backup_backup_dest = 'file:///data/backup_backup_nfs';
```
Save a secondary backup for the backup whose piece_id is 1 to the file:///data/backup_backup_nfs directory.
```
obclient> ALTER SYSTEM BACKUP BACKUPPIECE 1 backup_backup_dest = 'file:///data/backup_backup_nfs';
```

Perform secondary backup on multiple backup directories

Run the following commands to perform secondary backup on multiple backup directories:

Perform secondary backup on all directories or specified directories in the backup set.

obclient> ALTER SYSTEM BACKUP BACKUPSET ALL [backup_backup_dest = 'xxxxx'];

obclient> ALTER SYSTEM BACKUP BACKUPSET ALL NOT BACKED UP N TIMES backup_backup_dest = 'xxxxx';

Perform secondary backup on all directories or specified directories in the backup piece.

obclient> ALTER SYSTEM BACKUP BACKUPPIECE ALL [backup_backup_dest = 'xxxxx'];

obclient> ALTER SYSTEM BACKUP BACKUPPIECE ALL NOT BACKED UP N TIMES backup_backup_dest = 'xxxxx';

In the commands:

ALL indicates that all backup_set_id and piece_id directories whose file_status is AVAILABLE will be included in the secondary backup.
The NOT BACKED UP N TIMES parameter indicates that data that has been backed up N times will not be included in the secondary backup. N indicates the number of times.
If the NOT BACKED UP N TIMES parameter is specified in the command, the backup_backup_dest parameter must also be specified. Otherwise, the backup_backup_dest parameter does not need to be specified, and the backup data is archived to the directory specified by the backup_backup_dest configuration item by default.