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NAME

       cdbackup - Streaming backup to CD-R(W)/DVR-R(W)

SYNOPSIS

       cdbackup [-mvwCDRVX] [-d device] [-r scsi-dev] [-s speed]
                [-i image] [-p num] [-l size] [-a label]
                [-c command] [-- cdrecord-options]

DESCRIPTION

       cdbackup  is  a  utility  to make streaming backups to CD-R(W)/DVD-R(W)
       disks. It’s designed to work with any  backup  tool  which  writes  the
       backup to stdout (like tar/cpio/afio).

       NOTE:  this  program  REQUIRES that a recent version of cdrecord(1) (or
       cdrecord-ProDVD for DVD support) is present in the PATH.

       While you can perfectly append several sessions  on  CD-R(W)  media,  I
       didn’t  manage  to make this work on DVD-R(W) media. To allow multiple,
       separate backups on these media, the concept of virtual images has been
       introduced.
       A  virtual  image  is  a  plain  file  on your harddisk. You can append
       several backups to an image and after completing your  backup  session,
       the  image  is  dumped to CDR/DVD media in one burning session. You can
       dump the same image multiple times too, if you want redundancy  on  the
       CDR/DVD media.
       Virtual  image  files  are  never deleted by cdbackup. After dumping an
       image, you have to delete it by your self.

       WARNING! When using this program under Linux, be sure not to  use  dump
       on  a  mounted  filesystem.  This  has  a  high  potential for creating
       corrupted backups. As of kernel version 2.4.19, this has not been fixed
       and  it  may  not  be fixed at all.  You can read Linus statement about
       this                                                                 at
       <http://search.alphanet.ch/cgi-bin/search.cgi?max_results=10&type=long&msgid=Pine.LNX.4.21.0104270953280.2067-100000@penguin.transmeta.com&domain=ml-linux-kernel>

OPTIONS

       -d device
              The device name which is used for reading things  like  the  TOC
              from a (partly written) media.
              (default: /dev/burner)

       -r scsi-device
              The   scsi   device   which   is   passed  to  cdrecord(1)  (via
              dev=scsi-device).  Must  be  given  as  three,  comma  separated
              number: scsibus,target,lun.
              (default:  none  or  the  contents  of  the environment variable
              CDR_DEVICE)

       -s speed
              The  writing  speed  which  is  passed   to   cdrecord(1)   (via
              speed=speed).
              (default:   4  or  the  contents  of  the  environment  variable
              CDR_SPEED)

       -p num The number of sectors (of 2048 byte) to  use  for  padding  (see
              cdrecord(1) padsize).
              (default: 15)

       -X     Enables  the  use  of  CDROM XA2 mode in cdrecord(1). By default
              CDROM mode 1 is used. The default is possibly  causing  problems
              during   restore   on   certain  kernel  version/CDROM  hardware
              combinations at the end of the last session  on  a  media.  Sony
              drives doesn’t support CDROM XA 2 mode (see cdrecord(1) -multi).

       -R     Enables DVD writing mode. Cdrecord-ProDVD is used  to  burn  DVD
              media,  but it’s called through a script called "dvdrecord". You
              should set your cdrecord-ProDVD  key  and  call  cdrecord-ProDVD
              from there.
              Remember  that  you cannot write multiple sessions to DVD media.
              Either you stick with one backup per media or you  have  to  use
              virtual images.
              In DVD mode the options -p and -X have no effect.

       -i image
              Enables  virtual image mode. The backup stream is written to the
              given image file. The file is created if it doesn’t exists. It’s
              mandatory to give an explicit media size with -l. Take care that
              the created virtual image isn’t larger that the media  size  you
              want  to  dump  it  later.   You  can add up to 96 backups to an
              virtual image.
              If the backup extends the specified  media  size  and  you  have
              enabled  multi-disk  mode,  additional  images files are created
              (the filenames are derived from the initial image name by adding
              a dot and a decimal number).
              (default: none)

       -w     Dump  the  virtual  image specified with -i to real media. Image
              dumps are written as single sessions always. If you have enabled
              multi-disk mode and additional images are found, you’re prompted
              for media change, so that you can dump all images in turn.
              Virtual images (even when dumped to media)  are  not  compatible
              with older cdbackup versions.

       -l size
              For  normal  operation  the media size is auto-detected from the
              cdrecord ATIP information. If this fails or  for  virtual  image
              mode  use  this  option  to  set the media size. This is used to
              calculate how much data can be stored on the media.
              By default the given value is taken as megabytes. You can append
              a   single   letter   to  the  number  to  select:  (k)ilobytes,
              (m)egabytes,  (g)igabytes  or  (s)ectors  (e.g.   170k,   4488m,
              350000s).
              (default: auto-detect)

       -C     Disables  creation  of  the  datablock CRC checksum. There is no
              real reason to use this option,  unless  you  can’t  efford  the
              extra 0,2% media space that is used to store the checksum.
              Although the on-disk layout of checksummed backups is different,
              they are  fully  backwards  compatible  with  older  version  of
              cdbackup,  but  obviously  older versions can’t check the backup
              integrity.

       -a label
              A text label to identify the backup set. The first 32 characters
              of this string are save with the backup.
              (default: "CDBackup Track")

       -c command
              The command which is executed whenever cdbackup needs to request
              a new media in multi-disk mode. This command (or script)  should
              prompt  the  user and return after the recording device is ready
              again. The command receives one argument, which  is  the  device
              name  passed  with -d. This can be used to issue commands to the
              device like ejecting the media.
              (default: use internal diskchange prompt)

       -m     Enables multi-disk mode. When the current media is filled, a new
              media  is requested (see option -c) and the backup is continued.
              Backups can only be continued to empty  media,  this  means  you
              cannot insert a partly filled media for continuation.

       -v     Enables verbose mode.

       -D     Enables DEBUG output (probably not useful for normal use).

       -V     Prints out version information and exits.

       -- cdrecord-options
              Pass following options to cdrecord(1).

EXAMPLES

       To  create  a tar archive of /home and output it to a 700 MB CD-R(W) on
       /dev/scd0 (scsi device 2,0):

              tar cvf - /home | cdbackup -d /dev/scd0 -r 2,0 -l 700  -a  "Test
              Backup"

       To  create  a tar archive of /usr and output it to a series (multi-disk
       mode) of 650 MB CD-R(W) on /dev/sr1 (scsi device  1,4,0)  with  writing
       speed 12 and verbose output:

              tar cf - /usr | cdbackup -d /dev/sr1 -r 1,4,0 -s 12 -m -v

       To create a backup on a virtual image:

              tar cf - /usr | cdbackup -i /tmp/vimage -l 4488m

       Add another backup to the same virtual image (with multi-disk mode):

              tar cf - /home | cdbackup -i /tmp/vimage -l 4488m

       Dump  the  virtual  image  to  one (or several) DVD media on /dev/cdrom
       (scsi-ide device 0,0,0), enabling BURNFREE:

              cdbackup -i /tmp/vimage -w -R -d /dev/cdrom -r 0,0,0 -s 4 -m  --
              driveropts=burnfree

KNOWN PROBLEMS

       Certain combinations of CDROM drivers and kernel versions are causing a
       problem when restoring data. The restore process aborts  with  an  read
       error  close  to the end of the session, while the data on the media is
       perfectly good.

       All CDR sessions written in track-at-once mode  (which  is  unavoidable
       for  multisessions)  end in at least two unreadable runout sectors (for
       additional information refer to the file README.copy from the  cdrecord
       package).  As the kernel does some readahead on the device, it stumbles
       over these unreadable sectors before reaching the actual end of data.

       Some drivers are reporting to syslog but doesn’t pass the error to  the
       application,   while  others  make  the  application  fail.  From  user
       feedback, it seems that pure SCSI setups are mostly working fine, while
       ide-scsi setups are likely to fail.

       The  author isn’t able to provide a full solution, but some hints which
       may help:

       1.     Update to a recent kernel.

       2.     Disable kernel readahead with option -R when restoring.

       3.     Increase the padsize with option -p. Use values >= 128.

       4.     Use option -X if your writer supports this (Sony drives  doesn’t
              supports this mode).

       Please  contact the author if you can contribute additional information
       about the problem.

AUTHORS

       Stefan Hülswitt <s.huelswitt@gmx.de>

SEE ALSO

       cdrestore(1), cdrecord(1)

LICENSE

       Copyright (c) 2000-2004 Craig Condit, Stefan Hülswitt.

       Redistribution and use in source and  binary  forms,  with  or  without
       modification,  are permitted provided that the following conditions are
       met:

       1.     Redistributions of source code must retain the  above  copyright
              notice, this list of conditions and the following disclaimer.

       2.     Redistributions   in   binary  form  must  reproduce  the  above
              copyright notice, this list  of  conditions  and  the  following
              disclaimer  in the documentation and/or other materials provided
              with the distribution.

       THIS SOFTWARE IS PROVIDED BY THE AUTHOR ‘‘AS IS’’ AND  ANY  EXPRESS  OR
       IMPLIED   WARRANTIES,  INCLUDING,  BUT  NOT  LIMITED  TO,  THE  IMPLIED
       WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE  ARE
       DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
       ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR  CONSEQUENTIAL
       DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
       OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR  BUSINESS  INTERRUPTION)
       HOWEVER  CAUSED  AND  ON  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
       STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR  OTHERWISE)  ARISING
       IN  ANY  WAY  OUT  OF  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
       POSSIBILITY OF SUCH DAMAGE.