&author.jht; May 28, 2008 Managing TDB Files Features and Benefits tdb Trivial Database Samba uses a lightweight database called Trivial Database (tdb) in which it stores persistent and transient data. Some tdb files can be disposed of before restarting Samba, but others are used to store information that is vital to Samba configuration and behavior. The following information is provided to help administrators who are seeking to better manage their Samba installations. tdb corrupted backup restore Those who package Samba for commercial distribution with operating systems and appliances would do well to take note that tdb files can get corrupted, and for this reason ought to be backed up regularly. An appropriate time is at system shutdown (backup) and startup (restore from backup). NTDB As of Samba 4.1, the NTDB format can be used if 'use ntdb' is set. In this case, tdb files are automatically converted to ntdb files (with the .ntdb extension). The old .tdb file is turned into a dangling symlink to 'This is now in an NTDB' to prevent it being accidentally used). The table indicates what databases are currently available as NTDB files. Samba's Trivial Database Files File namePreserveNTDBDescriptionaccount_policy.tdbYN NT account policy settings such as pw expiration, etc...brlock.tdbNN Byte range locks.browse.datNN Browse lists - gets rebuilt automatically.connections.tdbNN Share connections. Used to enforce max connections, etc.gencache.tdbNN Generic caching database.group_mapping.tdbYN Stores group mapping information. Not used when using LDAP backend. lang_en.tdbYN Stores language encoding information.locking.tdbNN Stores share mode and oplock information.login_cache.tdbNN Keeps a log of bad pw attempts.messages.tdbNN Used to keep track of Samba internal messaging.netsamlogon_cache.tdbYN Cache of user net_info_3 struct from net_samlogon() requests from domain member machines. ntdrivers.tdbYN Stores installed printer driver information.ntforms.tdbYN Stores installed printer forms information.ntprinters.tdbYN Stores installed printers information.printing directoryYN Directory containing tdb per print queue of cached lpq output.registry.tdbYN Windows registry skeleton (connect via regedit.exe).sessionid.tdbNN Session information to support utmp = yes capabilities.share_info.tdbYN Stores share-level ACL configuration settings. Default ACL is Everyone - Full Control. unexpected.tdbNN Unexpected packet queue needed to support windows clients that respond on a different port that the originating reques. winbindd_cache.tdbNN Winbind's cache of user lists.winbindd_idmap.tdbYN Winbind's local IDMAP database.wins.datNN WINS database iused only when wins support = yes has been set. This gets rebuilt or updated at every restart. wins.tdbYN The working permanent storage for all WINS data. This database is used only when wins support = yes has been set in the &smb.conf; file. Note: This retains all manually configured WINS entries. Manual setting can be done use the net utility. secrets.tdbYY This tdb file stores internal settings such as the machine and the domain SID, secret passwords that are used with LDAP, the machine secret token, etc. This is an essential file that is stored in a secure area. Vendors locate this in various folders. Check smbd -b to find its location on your system. schannel_store.tdbYY This stores secure channel access token information used with SMB signing. passdb.tdbYN This stores the Samba SAM account information when using a tdbsam password backend.
Managing TDB Files The tdbbackup utility is a tool that may be used to backup samba tdb files. This tool may also be used to verify the integrity of the tdb files prior to Samba startup or during normal operation. If it finds file damage it will search for a prior backup the backup file from which the damaged tdb file will be restored. The tdbbackup utility can safely be run at any time. It was designed so that it can be used at any time to validate the integrity of tdb files, even during Samba operation. It is recommended to backup all tdb files as part of the Samba start-up scripts on a Samba server. The following command syntax can be used: myserver# > cd /var/lib/samba myserver@ > tdbbackup *.tdb The default extension is .bak. Any alternate extension can be specified by executing tdbbackup -s 'new_extension' *.tdb as part of your startup script.