15.5 Backup and Recovery Problems

Backup or restore fails

For backup failures, check path permissions for the server process’s OS account, available space, existing backups at the same path, and server logs.

SELECT * FROM V$STORAGE_USAGE;

machadmin -e
tail -100 "$MACHBASE_HOME/trc/machbase.trc"

Restoration is destructive: it replaces the existing physical database. Stopping the running server alone is insufficient; restoration is rejected if the current database still exists. The following is a conceptual checklist, not commands to copy into production.

1. Verify the recovery target, backup path, version, and checksums.
2. Obtain approval for preserving the current database and defining rollback conditions.
3. Shut down the server normally.
4. Follow the approved procedure to remove the current physical database.
5. Run machadmin restore.
6. Start the server and run application validation queries.

machadmin -d destroys the current database. Do not run it without a backup and explicit approval. For exact restoration syntax and restrictions, see BACKUP/RESTORE/MOUNT Syntax.

Checking a backup image or successfully mounting it is only preliminary validation and does not guarantee complete recoverability. Regularly restore and validate applications in a separate environment.

Mounting fails

Check current mounts, a unique alias, the backup path, and read permissions for the server process.

SELECT * FROM V$STORAGE_MOUNT_DATABASES;

The current syntax places the alias after the backup path.

MOUNT DATABASE '/backup/sc15_snapshot' TO backup_check;
SELECT COUNT(*) FROM backup_check.sys.target_table;
UMOUNT DATABASE backup_check;

Distinguish alias conflicts, unsupported editions, incompatible backups, and mounted databases in use. Do not forcibly delete files or modify server metadata.