vxdco(1M)                        VxVM 3.5                         vxdco(1M)
                                 1 Jun 2002



 NAME    [Toc]    [Back]
      vxdco - perform operations on DCO objects and DCO volumes

 SYNOPSIS    [Toc]    [Back]
      vxdco [-g diskgroup] att volume dco

      vxdco [-g diskgroup] attlogvol dco dco_volume

      vxdco [-g diskgroup] [-o rm] dis dco

      vxdco [-g diskgroup] [-o rm] dislogvol dco

      vxdco [-g diskgroup] -o force enable dco

 DESCRIPTION    [Toc]    [Back]
      The vxdco command is used to manipulate data change objects (DCO
      objects or DCOs) and DCO volumes that allow the use of Persistent
      FastResync with volumes.

      The att operation attaches a DCO object, dco, to a volume, volume.  If
      the DCO object has an associated DCO volume, you can use the command
      vxvol set fmr=on volume to enable Persistent FastResync on the volume
      after the attP operation has completed.

      The attlogvol operation associates a DCO volume, dco_volume, with a
      DCO object, dco.  If the DCO object is already attached to a volume,
      you can use the command vxvol set fmr=on volume to enable Persistent
      FastResync on the volume after the attlogvolP operation has completed.

      The dis operation dissociates a DCO object, dco, from a volume, and
      disables FastResync on that volume.  If the -o rm option is specified,
      the DCO object, the DCO volume, its plexes and associated subdisks are
      removed in the same operation.

      The dislogvol operation dissociates a DCO volume from a DCO object,
      dco, and disables FastResync on the parent volume.  If the -o rm
      option is specified, the DCO volume, its plexes and associated
      subdisks are removed in the same operation.

      If an error occurs while reading or writing a DCO volume, it is
      detached and the badlog flag is set on the DCO.  (You can use one of
      the options -a, -F or -m to vxprint to check if the badlog flag is set
      on a DCO.) The -o force enable operation clears the badlog flag on the
      DCO.

      The following command sequence demonstrates how to recover the DCO
      volume that tracks the top-level volume vol1 in the disk group egdg:

           vxdco -g egdg -o force enable vol1_dco
           vxvol -g egdg stop vol1
           vxvol -g egdg start vol1



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 vxdco(1M)                        VxVM 3.5                         vxdco(1M)
                                 1 Jun 2002



      Here vol1_dco is the DCO associated with vol1.

      Caution: Only use the -o force enable operation if you are certain
      that no writes have gone to the volume since the error occurred that
      caused its DCO volume to become detached.  Otherwise, data corruption
      may result.

      The -g diskgroup option specifies the disk group to which the parent
      volume, DCO object, and DCO volume belong.

      You can use the make keyword to vxassist to create a volume with an
      attached DCO object and DCO volume.  You can also use the addlog
      keyword to vxassist to create and add a DCO object and DCO volume to
      an existing volume.  vxdco may then be used to dissociate a DCO object
      from its parent volume, and subsequently reattach it if the DCO object
      and DCO volume have not been removed.

      The vxdco command is also used by vxassist and vxplex to handle the
      DCO objects and DCO volumes that are associated with volumes. The
      vxmake command is used to create DCO objects, which can be specified
      using output from vxprint.

      Note: When using disk group move, split and join (see vxdg(1M)) to
      move volumes or snapshot volumes between disk groups, take care to
      ensure that the DCO volumes accompany their parent volumes.

 EXIT CODES    [Toc]    [Back]
      The vxdco utility exits with a non-zero status if the attempted
      operation fails. A non-zero exit code is not a complete indicator of
      the problems encountered, but rather denotes the first condition that
      prevented further execution of the utility.

      See vxintro(1M) for a list of standard exit codes.

 NOTES    [Toc]    [Back]
      When a volume is attached to a DCO as its log volume, its device nodes
      are deleted. If vxdco dislogvol is subsequently used to dissociate the
      log volume from the DCO, the device nodes are not recreated.

 SEE ALSO    [Toc]    [Back]
      vxassist(1M), vxdg(1M), vxintro(1M), vxmake(1M), vxplex(1M),
      vxprint(1M), vxvol(1M)


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