DCM logging in DCO

Last published : Sep 18, 2026
In InfoScale 7.4.1 and prior releases, when replication is configured, a DCM log is associated as separate log plex to each data volume in the RVG. Starting with version 7.4.2, InfoScale allows you to maintain DCM logs as per-volume FMR maps inside the DCO that is associated with the corresponding data volumes.
Associating a Data Change Map to a data volume
Data Change Map can be associated to a data volume in one of the following ways:
  • DCM logging in DCO
  • DCM logging using DCM log plexes
Starting with InfoScale version 7.4.2, for new replication setups, DCM logs are by default allocated as per-volume FMR maps in DCO.
The setups, where older version of InfoScale is upgraded and replication is already configured, continue to use the pre-configured DCM log plexes. In such a case, you can choose to either use the DCM logging using DCM log plexes or configure DCM logging in DCO.
You can use the vxprint -Vl command to verify what type of DCM logging is enabled in your setup. The presence of the dcm_in_dco flag in the output of the vxprint command indicates that DCM logging is configured in DCO. If the flag is not set and DCM log plexes are associated with data volumes under the RVG, DCM logging is set to use DCM log plexes.
You can use the pre-existing vradmin createpri, vradmin addsec, and vradmin addvol commands to configure DCM logging in DCO. You can also use the -dcmplex option with these commands to change the configuration to use DCM log plexes even for new replication configurations.
Enabling DCM logging using DCM log plexes in a new setup
Starting with InfoScale 7.4.2, for a new replication setup, DCM logging is configured in DCO by default. However, you can choose to configure DCM log plexes.
To use DCM log plexes, perform the following steps:
  1. Setup the primary RVG.
Related information

vradmin -g -dcmplex createpri

  1. Setup and associate secondary RVG.

vradmin -g -dcmplex addsec

  1. Add data volumes to RVG

vradmin -g -dcmplex addvol

Enabling DCM logging in DCO after upgrade for pre-configured replication
When you upgrade InfoScale from an older version and replication is already configured, the setup continues to use the preconfigured DCM log plexes.
Perform the following steps to enable DCM logging in DCO in such upgraded setups.
  1. Stop replication

vradmin - g stoprep

  1. Un-configure replication by removing the secondary and the primary RVG.

vradmin - g delsec

vradmin - g delpri

  1. Remove DCM log plexes

vxassist - g remove log logtype=dcm nlog=<#_dcm_plexes>

  1. Re-configure replication

vradmin -g createpri

vradmin -g addsec

vradmin - g -a startrep

For details, refer to Veritas InfoScale Replication Administrator's Guide.