Selection of the number of configuration copies for a disk group is based on a trade-off between redundancy and performance. As a general rule, reducing the number of configuration copies in a disk group speeds up initial access of the disk group, initial startup of the vxconfigd daemon, and transactions that are performed within the disk group. However, reducing the number of configuration copies also increases the risk of complete loss of the configuration database, which results in the loss of all objects in the database and of all data in the disk group.

The default policy for configuration copies in the disk group is to allocate a configuration copy for each controller identified in the disk group, or for each target that contains multiple addressable disks. This provides a sufficient degree of redundancy, but can lead to a large number of configuration copies under some circumstances. If this is the case, we recommended that you limit the number of configuration copies to a maximum of 4. Distribute the copies across separate controllers or targets to enhance the effectiveness of this redundancy.

To set the number of configuration copies for a new disk group, use the nconfig operand with the vxdg init command.

See the vxdg(1M) manual page for details.

You can also change the number of copies for an existing group by using the vxedit set command. For example, to configure five configuration copies for the disk group, bigdg, use the following command:

# vxedit set nconfig=5 bigdg 

See the vxedit(1M) manual page.