Host TopologyHost topology is the organization of hosts, host groups, and host interfaces configured for a storage array. You can viewthe host topology in the Host Mappings tab of the AMW. For more information, see Using The Host Mappings Tab.The following tasks change the host topology:• Moving a host or a host connection• Renaming a host group, a host, or a host connection• Adding a host connection• Replacing a host connection• Changing a host typeThe MD Storage Manager automatically detects these changes for any host running the host agent software.Starting Or Stopping The Host Context AgentThe Host Context Agent discovers the host topology. The Host Context Agent starts and stops with the host. Thetopology discovered by the Host Context Agent can be viewed by clicking Configure Host Access (Automatic) in theConfigure tab in the MD Storage Manager.You must stop and restart the Host Context Agent to see the changes to the host topology if:• A new storage array is attached to the host server.• A host is added while turning on power to the RAID controller modules.To start or stop the Host Context Agent on Linux, enter the following commands at the prompt:SMagent startSMagent stopYou must stop and then restart SMagent after:• Moving a controller offline or replacing a controller.• Removing host-to-array connections from or attaching host-to-array connections to a Linux host server.To start or stop the Host Context Agent on Windows:1. Do one of the following:– Click Start → Settings → Control Panel → Administrative Tools → Services– Click Start → Administrative Tools → Services2. From the list of services, select Modular Disk Storage Manager Agent.3. If the Host Context Agent is running, click Action → Stop, then wait approximately 5 seconds.4. Click Action → Start.I/O Data Path ProtectionYou can have multiple host-to-array connections for a host. Ensure that you select all the connections to the array whenconfiguring host access to the storage array.NOTE: See the Deployment Guide for more information on cabling configurations.57
