DB_ARCHIVE(1) BerkeleyDB Utilities DB_ARCHIVE(1)
NAME
db_archive - Find unused log files for archival
SYNOPSIS
db_archive [-adlsVv] [-h home] [-P password]
DESCRIPTION
The db_archive utility writes the pathnames of log files that are no
longer in use (for example, no longer involved in active transactions),
to the standard output, one pathname per line. These log files should
be written to backup media to provide for recovery in the case of cata-
strophic failure (which also requires a snapshot of the database
files), but they may then be deleted from the system to reclaim disk
space.
OPTIONS
-a Write all pathnames as absolute pathnames, instead of relative
to the database home directories.
-d Remove log files that are no longer needed; no filenames are
written. Automatic log file removal is likely to make cata-
strophic recovery impossible.
-h home
Specify a home directory for the database environment; by
default, the current working directory is used.
-l Write out the pathnames of all the database log files, whether
or not they are involved in active transactions.
-P password
Specify an environment password. Although Berkeley DB utilities
overwrite password strings as soon as possible, be aware there
may be a window of vulnerability on systems where unprivileged
users can see command-line arguments or where utilities are not
able to overwrite the memory containing the command-line argu-
ments.
-s Write the pathnames of all the database files that need to be
archived in order to recover the database from catastrophic
failure. If any of the database files have not been accessed
during the lifetime of the current log files, db_archive will
not include them in this output.
It is possible that some of the files to which the log refers
have since been deleted from the system. In this case, db_ar-
chive will ignore them. When db_recover is run, any files to
which the log refers that are not present during recovery are
assumed to have been deleted and will not be recovered.
-V Write the library version number to the standard output, and
exit.
-v Run in verbose mode, listing the checkpoints in the log files as
they are reviewed.
Log cursor handles (returned by the DB_ENV->log_cursor method) may have
open file descriptors for log files in the database environment. Also,
the Berkeley DB interfaces to the database environment logging subsys-
tem (for example, DB_ENV->log_put and DB_TXN->abort) may allocate log
cursors and have open file descriptors for log files as well. On oper-
ating systems where filesystem related system calls (for example,
rename and unlink on Windows/NT) can fail if a process has an open file
descriptor for the affected file, attempting to move or remove the log
files listed by db_archive may fail. All Berkeley DB internal use of
log cursors operates on active log files only and furthermore, is
short-lived in nature. So, an application seeing such a failure should
be restructured to close any open log cursors it may have, and other-
wise to retry the operation until it succeeds. (Although the latter is
not likely to be necessary; it is hard to imagine a reason to move or
rename a log file in which transactions are being logged or aborted.)
The db_archive utility uses a Berkeley DB environment (as described for
the -h option, the environment variable DB_HOME, or because the utility
was run in a directory containing a Berkeley DB environment). In order
to avoid environment corruption when using a Berkeley DB environment,
db_archive should always be given the chance to detach from the envi-
ronment and exit gracefully. To cause db_archive to release all envi-
ronment resources and exit cleanly, send it an interrupt signal (SIG-
INT).
The DB_ENV->log_archive method is the underlying method used by the
db_archive utility. See the db_archive utility source code for an
example of using DB_ENV->log_archive in a IEEE/ANSI Std 1003.1 (POSIX)
environment.
EXIT STATUS
The db_archive utility exits 0 on success, and >0 if an error occurs.
ENVIRONMENT
DB_HOME
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, as
described in DB_ENV->open.
NOTES
If the application(s) that use the environment make use of any of the
following methods:
DB_ENV->add_data_dir
DB_ENV->set_data_dir
DB_ENV->set_lg_dir
then in order for this utility to run correctly, you need a DB_CONFIG
file which sets the proper paths using the add_data_dir, or set_lg_dir
configuration parameters.
SEE ALSO
db_checkpoint(1) db_deadlock(1) db_dump(1) db_hotbackup(1) db_log_ver-
ify(1) db_load(1) db_printlog(1) db_recover(1) db_replicate(1)
db_stat(1) db_tuner(1) db_upgrade(1) db_verify(1)
BerkeleyDB 5.3.28 06 December 2016 DB_ARCHIVE(1)