db_recover(8)db_recover(8)NAMEdb_recover - Restores the database to a consistent state (Enhanced
Security)
SYNOPSIS
/usr/tcb/bin/db_recover [-cv] [-h home]
OPTIONS
Failure was catastrophic. Specify a home directory for the database.
The correct directory for enhanced security is /var/tcb/files. Write
out the pathnames of all of the database log files, whether or not they
are involved in active transactions. Run in verbose mode.
DESCRIPTION
A customized version of the Berkeley Database (Berkeley DB) is embedded
in the operating system to provide high-performance database support
for critical security files. The DB includes full transactional support
and database recovery, using write-ahead logging and checkpointing to
record changes.
The db_recover utility runs after an unexpected system failure to
restore the security database to a consistent state. All committed
transactions are guaranteed to appear after db_recover has run, and all
uncommitted transactions are completely undone. DB recovery is normally
performed automatically for the security files as part of system
startup.
In the case of catastrophic failure, an archival copy, or snapshot of
all database files must be restored along with all of the log files
written since the database file snapshot was made. (If disk space is a
problem, log files may be referenced by symbolic links).
If the failure was not catastrophic, the files present on the system at
the time of failure are sufficient to perform recovery.
If log files are missing, db_recover identifies the missing log files
and fails, in which case the missing log files need to be restored and
recovery performed again.
The db_recover utility attaches to one or more of the Berkeley DB
shared memory regions. In order to avoid region corruption, it should
always be given the chance to detach and exit gracefully. To cause
db_recover to clean up after itself and exit, send it an interrupt sig‐
nal (SIGINT).
RETURN VALUES
The db_recover utility exits 0 on success, and >0 if an error occurs.
ENVIRONMENT VARIABLES
If the -h option is not specified and the environment variable DB_HOME
is set, it is used as the path of the database home. The home directory
for security is /var/tcb/files.
FILES
/var/tcb/files/auth.db
/var/tcb/files/dblogs/*
SEE ALSO
Commands: db_archive(8), db_checkpoint(8), db_printlog(8), db_dump(8),
db_load(8), db_stat(8), secconfig(8)db_recover(8)