tdbrestore

The tdbrestore command is part of the Samba suite, specifically used for restoring Trivial Database (TDB) files. TDB is a simple database format used by Samba to store various configurations and state information. The most common use case for tdbrestore is to recover or restore the TDB database files, which can be crucial for Samba's operation, such as restoring the Samba user database, secrets database, and other related Samba state files.

Overview of tdbrestore

tdbrestore is used primarily when a Samba TDB database is corrupted, missing, or needs to be restored from a backup. This tool allows administrators to restore TDB database files from a backup into their respective Samba configuration, enabling the system to recover from database failures.

General Syntax:

tdbrestore [options] <db-file>

Where:

• <db-file> is the path to the TDB database file you want to restore.

• The tool restores data from the backup to the given TDB file.

Common Use Cases

• Restoring TDB Files After Corruption: If a TDB file (e.g., secrets.tdb or passdb.tdb) becomes corrupted, tdbrestore allows you to restore from a previously created backup.

• Recovering User Data: If user data in a passdb.tdb file gets corrupted, it can be restored using the backup.

• Restoring Samba Secrets: Samba uses the secrets.tdb file to store various secrets, including the machine's password for authenticating with other services. If this file is corrupted, it can be restored.

Key Options for tdbrestore

• --help: Displays help for the command and available options.

• --backup: Specifies the backup file to restore from.

• --no-rename: Optionally prevents renaming of files.

• --recovery: Used to restore a TDB file during a recovery process, such as after a crash.

Example Usage

1. Restoring from a Backup

Suppose you have a backup of your passdb.tdb file and want to restore it to its original location. Here's how you can do it:

tdbrestore --backup=/path/to/backup/passdb.tdb /var/lib/samba/private/passdb.tdb

This restores the passdb.tdb from the backup to its original location.

2. Restoring a Specific TDB Database File

If you want to restore a specific TDB database file (like secrets.tdb), you would use:

tdbrestore /path/to/secrets.tdb

This restores the file to its default location based on the Samba configuration.

3. Viewing Available Options

To see the available options for tdbrestore and get more details, run:

tdbrestore --help

This command will output detailed information about the command and the available options.

Typical Use Cases for TDB Databases in Samba

• secrets.tdb: Stores secrets such as the machine password used for communication between the Samba server and the domain.

• passdb.tdb: Stores user account data, including passwords and other information related to Samba users.

• tdb Files for Print Spoolers: Samba uses TDB files for spool management when printing over the network.

Conclusion

tdbrestore is a vital tool for administrators who need to recover Samba's TDB databases from backups. Whether it’s recovering user data, restoring Samba secrets, or dealing with corruption, tdbrestore helps ensure that Samba services can be quickly restored and remain operational. Regular backups of critical TDB files are highly recommended to avoid potential data loss.