Ubuntu Manpage: cback - Local and remote backups to CD-R/CD-RW media

NAME

       cback - Local and remote backups to CD-R/CD-RW media

SYNOPSIS

       cback [switches] action(s)

DESCRIPTION

The cback script provides the command-line interface for Cedar Backup. Cedar Backup is a
software package designed to manage system backups for a pool of local and remote
machines. Cedar Backup understands how to back up filesystem data as well as MySQL and
PostgreSQL databases and Subversion repositories. It can also be easily extended to
support other kinds of data sources.

Cedar Backup is focused around weekly backups to a single CD or DVD disc, with the
expectation that the disc will be changed or overwritten at the beginning of each week.
If your hardware is new enough, Cedar Backup can write multisession discs, allowing you to
add incremental data to a disc on a daily basis.

There are two kinds of machines in a Cedar Backup pool. One machine (the master) has a
CD-R or CD-RW drive on it and is where the backup is written to disc. The others
(clients) collect data to be written to disc by the master. Collectively, the master and
client machines in a pool are all referred to as peer machines. There are four actions
that take place as part of the backup process: collect, stage, store and purge. Both the
master and the clients execute the collect and purge actions, but only the master executes
the stage and store actions. The configuration file /etc/cback.conf controls the actions
taken during collect, stage, store and purge actions.

Cedar Backup also supports the concept of managed clients. Managed clients have their
entire backup process managed by the master via a remote shell. The same actions are run
as part of the backup process, but the master controls when the actions are executed on
the clients rather than the clients controlling it for themselves.

SWITCHES

-h, --help
Display usage/help listing.

-V, --version
Display version information.

-b, --verbose
Print verbose output to the screen as well writing to the logfile. When this option
is enabled, most information that would normally be written to the logfile will
also be written to the screen.

-q, --quiet
Run quietly (display no output to the screen).

-c, --config
Specify the path to an alternate configuration file. The default configuration
file is /etc/cback.conf.

-f, --full
Perform a full backup, regardless of configuration. For the collect action, this
means that any existing information related to incremental backups will be ignored
and rewritten; for the store action, this means that a new disc will be started.

-M, --managed
Include managed clients when executing actions. If the action being executed is
listed as a managed action for a managed client, execute the action on that client
after executing the action locally.

-N, --managed-only
Include only managed clients when executing actions. If the action being executed
is listed as a managed action for a managed client, execute the action on that
client, but do not execute the action locally.

-l, --logfile
Specify the path to an alternate logfile. The default logfile file is
/var/log/cback.log.

-o, --owner
Specify the ownership of the logfile, in the form user:group. The default
ownership is root:adm, to match the Debian standard for most logfiles. This value
will only be used when creating a new logfile. If the logfile already exists when
the cback script is executed, it will retain its existing ownership and mode. Only
user and group names may be used, not numeric uid and gid values.

-m, --mode
Specify the permissions for the logfile, using the numeric mode as in chmod(1).
The default mode is 640 (-rw-r-----). This value will only be used when creating a
new logfile. If the logfile already exists when the cback script is executed, it
will retain its existing ownership and mode.

-O, --output
Record some sub-command output to the logfile. When this option is enabled, all
output from system commands will be logged. This might be useful for debugging or
just for reference. Cedar Backup uses system commands mostly for dealing with the
CD recorder and its media.

-d, --debug
Write debugging information to the logfile. This option produces a high volume of
output, and would generally only be needed when debugging a problem. This option
implies the --output option, as well.

-s, --stack
Dump a Python stack trace instead of swallowing exceptions. This forces Cedar
Backup to dump the entire Python stack trace associated with an error, rather than
just progating last message it received back up to the user interface. Under some
circumstances, this is useful information to include along with a bug report.

-D, --diagnostics
Display runtime diagnostic information and then exit. This diagnostic information
is often useful when filing a bug report.

ACTIONS

       all    Take all normal actions (collect, stage, store, purge), in that order.

       collect
              Take the collect action, creating tarfiles for  each  directory  specified  in  the
              collect section of the configuration file.

       stage  Take  the  stage  action, copying tarfiles from each peer in the backup pool to the
              daily staging directory, based on the stage section of the configuration file.

       store  Take the store action, writing the daily staging directory to  disc  based  on  the
              store section of the configuration file.

       purge  Take  the  purge  action, removing old and outdated files as specified in the purge
              section of the configuration file.

       rebuild
              Rebuild the "this week's" disc  based  on  the  current  contents  of  the  staging
              directory.   This  option has been made available as a means to recover a disc that
              has been "trashed" due to a hardware or media error.

       validate
              Ensure that configuration is valid, but take no other  action.   Validation  checks
              that  the  configuration  file  can be found and can be parsed, and also checks for
              typical configuration problems, such  as  directories  that  are  not  writable  or
              problems with the target SCSI device.

RETURN VALUES

       Cedar Backup returns 0 (zero) upon normal completion, and six other error codes related to
       particular errors.

       1      The Python interpreter version is < 2.5.

       2      Error processing command-line arguments.

       3      Error configuring logging.

       4      Error parsing indicated configuration file.

       5      Backup was interrupted with a CTRL-C or similar.

       6      Error executing specified backup actions.

NOTES

The script is designed to run as root, since otherwise it's difficult to back up system
directories or write the CD or DVD device. However, pains are taken to switch to a backup
user (specified in configuration) when appropriate.

To use the script, you must specify at least one action to take. More than one of the
"collect", "stage", "store" or "purge" actions may be specified, in any arbitrary order.
The "all", "rebuild" or "validate" actions may not be combined with other actions. If
more than one action is specified, then actions will be taken in a sensible order
(generally collect, followed by stage, followed by store, followed by purge).

If you have configured any Cedar Backup extensions, then the actions associated with those
extensions may also be specified on the command line. If you specify any other actions
along with an extended action, the actions will be executed in a sensible order per
configuration. The "all" action never executes extended actions, however.

Note that there is no facility for restoring backups. It is assumed that the user can
deal with copying tarfiles off disc and using them to restore missing files as needed.
The user manual provides detailed intructions in Appendix C.

Finally, you should be aware that backups to CD or DVD can probably be read by any user
which has permissions to mount the CD or DVD drive. If you intend to leave the backup
disc in the drive at all times, you may want to consider this when setting up device
permissions on your machine. You might also want to investigate the encrypt extension.

FILES

       /etc/cback.conf - Default configuration file

       /var/log/cback.log - Default log file

BUGS

       There probably are bugs in this code.  However, it is in active use for  my  own  backups,
       and  I  fix problems as I notice them.  If you find a bug, please report it.  If possible,
       give me the output from --diagnostics, all of the error messages that the  script  printed
       into  its  log,  and  also any stack-traces (exceptions) that Python printed.  It would be
       even better if you could tell me how to reproduce the problem (i.e.  by  sending  me  your
       configuration file).

       Report bugs to <support@cedar-solutions.com>.

AUTHOR

       Written by Kenneth J. Pronovici <pronovic@ieee.org>.

COPYRIGHT

       Copyright (c) 2004-2010 Kenneth J. Pronovici.
       This  is  free software; see the source for copying conditions.  There is NO warranty; not
       even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.