DB_RECOVER(1) BerkeleyDB Utilities DB_RECOVER(1)
NAME
db_recover - Recover the database to a consistent state
SYNOPSIS
db_recover [-cefVv] [-h home] [-P password] [-t [[CC]YY]MMDDhhmm[.SS]]]
DESCRIPTION
The db_recover utility must be run after an unexpected application,
Berkeley DB, or system failure to restore the database to a consistent
state. All committed transactions are guaranteed to appear after
db_recover has run, and all uncommitted transactions will be completely
undone.
Note that this utility performs the same action as if the environment
is opened with the DB_RECOVER flag. If DB_RECOVER is specified on
environment open, then use of this utility is not necessary.
OPTIONS
-c Perform catastrophic recovery instead of normal recovery.
-e Retain the environment after running recovery. This option will
rarely be used unless a DB_CONFIG file is present in the home
directory. If a DB_CONFIG file is not present, then the regions
will be created with default parameter values.
-f Display a message on the standard output showing the percent of
recovery completed.
-h home
Specify a home directory for the database environment; by
default, the current working directory is used.
-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.
-t Recover to the time specified rather than to the most current
possible date. The timestamp argument should be in the form
[[CC]YY]MMDDhhmm[.SS] where each pair of letters represents the
following:
CC The first two digits of the year (the century).
YY The second two digits of the year. If "YY" is specified,
but "CC" is not, a value for "YY" between 69 and 99
results in a "CC" value of 19. Otherwise, a "YY" value
of 20 is used.
MM The month of the year, from 1 to 12.
DD The day of the month, from 1 to 31.
hh The hour of the day, from 0 to 23.
mm The minute of the hour, from 0 to 59.
SS The second of the minute, from 0 to 61.
If the "CC" and "YY" letter pairs are not specified, the values
default to the current year. If the "SS" letter pair is not
specified, the value defaults to 0.
-V Write the library version number to the standard output, and
exit.
-v Run in verbose mode.
In the case of catastrophic recovery, 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 will identify the missing log
file(s) and fail, in which case the missing log files need to be
restored and recovery performed again.
The db_recover 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_recover should always be given the chance to detach from the envi-
ronment and exit gracefully. To cause db_recover to release all envi-
ronment resources and exit cleanly, send it an interrupt signal (SIG-
INT).
EXIT STATUS
The db_recover 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_archive(1) db_checkpoint(1) db_deadlock(1) db_dump(1) db_hot-
backup(1) db_log_verify(1) db_load(1) db_printlog(1) db_replicate(1)
db_stat(1) db_tuner(1) db_upgrade(1) db_verify(1)
BerkeleyDB 5.3.28 06 December 2016 DB_RECOVER(1)