db_archive(1) BSD General Commands Manual db_archive(1)NAMEdb_archiveSYNOPSISdb_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.
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 over‐
write 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 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_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 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 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 sys‐
tems 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 oper‐
ates 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 trans‐
actions 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_ar‐
chive 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_archive utility source code for an example
of using DB_ENV->log_archive in a IEEE/ANSI Std 1003.1 (POSIX) environ‐
ment.
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 ALSOdb_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
