db5.3_hotbackup - Create "hot backup" or "hot
failover" snapshots
db5.3_hotbackup [-cDuVv] [-d data_dir ...] [-h home] [-l
log_dir] [-P password] -b backup_dir
The db5.3_hotbackup utility creates "hot backup" or
"hot failover" snapshots of Berkeley DB database environments.
The db5.3_hotbackup utility performs the following steps:
- 1.
- If the -c option is specified, checkpoint the source home database
environment, and remove any unnecessary log files.
- 2.
- If the target directory for the backup does not exist, it is created with
mode read-write-execute for the owner.
If the target directory for the backup does exist and the -u
option was specified, all log files in the target directory are removed;
if the -u option was not specified, all files in the target directory
are removed.
- 3.
- If the -u option was not specified, copy application-specific files found
in the database environment home directory, or any directory specified
using the -d option, into the target directory for the backup.
- 4.
- Copy all log files found in the directory specified by the -l option (or
in the database environment home directory, if no -l option was
specified), into the target directory for the backup.
- 5.
- Perform catastrophic recovery on the hot backup.
- 6.
- Remove any unnecessary log files from the hot backup.
The db5.3_hotbackup utility does not resolve pending transactions
that are in the prepared state. Applications that use DB_TXN->prepare
should specify DB_RECOVER_FATAL when opening the environment, and run
DB_ENV->txn_recover to resolve any pending transactions, when failing
over to the hot backup.
- -b
- Specify the target directory for the backup.
- -c
- Before performing the snapshot, checkpoint the source database environment
and remove any log files that are no longer required in that environment.
To avoid making catastrophic failure impossible, log file removal
must be integrated with log file archival.
- -d
- Specify one or more source directories that contain databases; if none is
specified, the database environment home directory will be searched for
database files. As database files are copied into a single backup
directory, files named the same, stored in different source directories,
could overwrite each other when copied into the backup directory.
- -h
- Specify the source directory for the backup, that is, the database
environment home directory.
- -l
- Specify a source directory that contains log files; if none is specified,
the database environment home directory will be searched for log
files.
- -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.
- -u
- Update a pre-existing hot backup snapshot by copying in new log files. If
the -u option is specified, no databases will be copied into the
target directory.
- -V
- Write the library version number to the standard output, and exit.
- -v
- Run in verbose mode, listing operations as they are done.
- -D
- Use the data directories listed in the DB_CONFIG configuration file in the
source directory. This option has three effects: First, if they do not
already exist, the specified data directories will be created relative to
the target directory (with mode read-write-execute owner). Second, all
files in the source data directories will be copied to the target data
directories. If the DB_CONFIG file specifies one or more absolute
pathnames, files in those source directories will be copied to the
top-level target directory. Third, the DB_CONFIG configuration file will
be copied from the +source directory to the target directory, and
subsequently used for configuration if recovery is run in the target
directory.
Care should be taken with the -D option and data
directories which are named relative to the source directory but are not
subdirectories (that is, the name includes the element "..")
Specifically, the constructed target directory names must be meaningful and
distinct from the source directory names, otherwise running recovery in the
target directory might corrupt the source data files.
It is an error to use absolute pathnames for data
directories or the log directory in this mode, as the DB_CONFIG
configuration file copied into the target directory would then point
at the source directories and running recovery would corrupt the
source data files.
The db5.3_hotbackup 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, db5.3_hotbackup should always be given the chance to detach
from the environment and exit gracefully. To cause db5.3_hotbackup to
release all environment resources and exit cleanly, send it an interrupt
signal (SIGINT).
The db5.3_hotbackup utility exits 0 on success, and >0 if an
error occurs.
- 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.
Oracle Corporation. This manual page was created based on the HTML
documentation for db_hotbackup from Sleepycat, by Thijs Kinkhorst
<thijs@kinkhorst.com>, for the Debian system (but may be used by
others).