Modifying the Agents and Their Resources

You can use the VCS Cluster Manager GUI, or enter VCS commands (the "ha" commands such as hastatus and haconf) from the command line, to modify the configuration of the resources managed by an agent. You can also edit the main.cf file directly, but you must reboot your system for the changes to take effect. An example main.cf file is located in the /etc/VRTSvcs/conf/sample_cvm directory.

It is advisable to use the VERITAS Cluster Server GUI to administer your cluster file system resources. See VERITAS Cluster Server Installation Guide for instructions on how to install the GUI, and the VERITAS Cluster Server User's Guide for detailed information on how to perform VCS administrative tasks.

Resources and Service Groups for File System Cluster Functionality

Managing cluster mounts through VCS requires various resources types, resources, and service groups. The VCS resource types required for VERITAS Volume Manager cluster functionality (or CVM) are:

• CVMCluster
• CVMVolDg

CVMCluster controls the overall operation of CVM. The agents of CVMCluster bring up the CVM cluster. Only one CVMCluster resource is required in a VCS environment. It is advisable to use the standard configuration procedure for CVM (see Cluster File System Administrative Interface) to add the CVMCluster resource. The procedure creates a service group named cvm and adds the resources to the configuration.

The VCS resource types required for cluster file system (CFS) functionality are:

• CFSfsckd
• CFSMount

CFSfsckd is a mandatory resource type for CFS functionality. CFSfsckd agents start the cluster file system check (fsck command) daemon, vxfsckd, which must be running for a cluster mount to succeed. As with CVMCluster, only one resource instance is required for CFSfsckd. You add these resources using the CFS configuration process (see The cfscluster Command), which adds the resources to the cvm service group.

Each CVMVolDg resource controls one shared disk group, and one or more shared volumes of that disk group. CVMVolDg resources enable the disk group and set the disk group activation mode. Each CFSMount resource controls the cluster mount of a shared volume on a specified mount point. CFSMount resources also keep track of mount options associated with the mount points.

These resource instances are not added automatically during the CFS configuration; you must add them as required using the CFS cluster administration commands. Note that CFSMount and CVMVolDg resources are not added to the cvm service group; those should be added to a different service group (see The cfsmntadm Command).

Resource and Service Group Dependencies

Dependencies between resources and service groups specify the order in which the resource and service group are brought online and taken offline, which must be done in correct sequence. The various resources and service groups required for CFS must follow these dependency (or link) rules:

• A CFSMount resource must depend on the corresponding CVMVolDg resource
• A service group containing the CVMVolDg resource must depend on the cvm service group