Configuration of the /etc/horcm.conf File

As used with the Sun Cluster Geographic Edition configuration, a Hitachi TrueCopy or Universal Replicator device group is a named entity consisting of sets of paired Logical Unit Numbers (LUNs). One member of each pair of LUNs is located in local storage on the primary cluster and the other member is located in local storage on a Sun Cluster Geographic Edition partner cluster. Data is written to one member of a pair of LUNs in local storage on the primary cluster and replicated to the other member of the pair on local storage on the secondary cluster. Each LUN in a pair is assigned the same name as the name that is assigned to the other LUN in the pair. Thus, data that is written to the LUN assigned the pair1 device name on the primary cluster is replicated to the LUN assigned the pair1 device name on the secondary cluster. Data that is written to the LUN assigned the pair2 device name on the primary cluster is replicated to the LUN assigned the pair2 device name on the secondary cluster.

On each storage-attached node of each cluster, pairs are given names and assigned to a device group in the /etc/horcm.conf file. Additionally, in this file, each device group is assigned a name that is the same on all storage-attached nodes of all clusters that are participating in a Sun Cluster Geographic Edition partnership.

In the /etc/horcm.conf file, you configure each Hitachi TrueCopy or Universal Replicator device group as a property of either the HORCM_DEV parameter or the HORCM_LDEV parameter. Depending on their intended use, you might configure one device group in the /etc/horcm.conf file as a property of HORCM_DEV and another device group as a property of HORCM_LDEV. However, a single device group can only be configured as a property of HORCM_DEV or of HORCM_LDEV. For any one device group, the selected parameter, HORCM_DEV or HORCM_LDEV, must be consistent on all storage-attached nodes of all clusters that are participating in the Sun Cluster Geographic Edition partnership.

Of the parameters that are configured in the /etc/horcm.conf file, only HORCM_DEV and HORCM_LDEV have requirements that are specific to the Sun Cluster Geographic Edition configuration. For information about configuring other parameters in the /etc/horcm.conf file, see the documentation for Hitachi TrueCopy and Universal Replicator.