db_archive(1) BSD General Commands Manual db_archive(1)
NAME
db_archive
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 catastrophic failure (which
also requires a snapshot of the database files), but they may then be deleted from the system to
reclaim disk space.
The options are as follows:
-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 catastrophic recovery impossible.
-h
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
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 arguments.
-s
Write the pathnames of all the database files that need to be archived in order to recover the data-base database
base from catastrophic failure. If any of the database files have not been accessed during the life-time lifetime
time 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 sys-tem. system.
tem. In this case, db_archive 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 recov-ered. recovered.
ered.
-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
subsystem (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 operating 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 otherwise 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 environment and exit gracefully. To cause db_archive to release
all environment resources and exit cleanly, send it an interrupt signal (SIGINT).
The DB_ENV->log_archive method is the underlying method used by the db_archive utility. See the db_ar-chive db_archive
chive utility source code for an example of using DB_ENV->log_archive in a IEEE/ANSI Std 1003.1 (POSIX)
environment.
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.
SEE ALSO
db_checkpoint(1), db_deadlock(1), db_dump(1), db_load(1), db_printlog(1), db_recover(1), db_stat(1),
db_upgrade(1), db_verify(1)
Darwin December 3, 2003 Darwin
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