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.

Cedar Backup                                        July 2010                                           cback(1)