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NBACKUP(1) Firebird documentation NBACKUP(1)


nbackup - Physical backup manager for Firebird



nbackup allows making incremental backups of firebird databases. It also allows database files to be locked for copying with OS tools like cp(1).


Locks database for filesystem copy.

Options of the -lock command:

Print database size (in database pages) after locking.
Unlocks previously locked database.
Fixup database after filesystem copy. This needs to be done on the target database before usage.
Create incremental backup of level level. Level 0 means full backup. Level N includes all the changes since the last backup of level N. file may be "stdout" meaning to write the backup data to the standard output.

Additional options to the -backup command:

Turns on or off direct I/O during database backup.

Direct I/O may be useful when database is much larger that RAM, because in that case using buffered I/O may cause replacing useful cache contents with database file contents, which are generally read only once.

Restore incremental backup. file0 is the level 0 backup, file1 is the level 1 backup and so on.

Additional -restore options:

Decompress backup file contents using the given command.

Note: -restore should be the last argument to nbackup followed only by database and file names. All other options must precede -restore or will be interpreted as backup file names.


User name for connecting to the firebird server.
Password for connecting to the firebird server.
Read password from specified file.
Do not run database-level triggers.



Additional documentation about nbackup and other Firebird utilities can be found on the Firebird Project website, <>.


Original idea is of Sean Leyne Designed and implemented by Nickolay Samofatov This work was funded through a grant from BroadView Software, Inc.

This manual page was written by Damyan Ivanov for the Debian project. Permission is granted to use this document, with or without modifications, provided that this notice is retained. If we meet some day, and you think this stuff is worth it, you can buy me a beer in return.

2020-12-25 Firebird 3.0