Creating Host Groups For Storeall Clients; Overview; How Host Groups Work; Creating A Host Group Tree - HP StoreAll 8800 Administrator's Manual

7 Creating host groups for StoreAll clients

Overview

A host group is a named set of StoreAll clients. Host groups provide a convenient way to centrally
manage clients. You can put different sets of clients into host groups and then perform the following
operations on all members of the group:
Create and delete mount points
Mount file systems
Prefer a network interface
Tune host parameters
Set allocation policies
Host groups are optional. If you do not choose to set them up, you can mount file systems on clients
and tune host settings and allocation policies on an individual level.
Use the Hostgroups window to view and manage host groups. To access this window, select
Hostgroups in the Navigator. Besides the name of the host group, the Hostgroups window displays
the following information:
Parent: If the host group is a child group, the name of the host group's parent in the group
hierarchy is displayed.
Domain: If defined, the subnet IP address used to assign HP StoreAll clients to this group is
displayed. A domain rule restricts host group membership to HP StoreAll clients on the cluster
subnet identified by this address.
To manage host groups using the CLI, see the ibrix_hostgroup command in the HP StoreAll
OS CLI Reference Guide.

How host groups work

In the simplest case, the host groups functionality allows you to perform an allowed operation on
all StoreAll clients by executing a command on the default clients host group with the CLI or
the GUI. The clients host group includes all StoreAll clients configured in the cluster.
NOTE: The command intention is stored on the Fusion Manager until the next time the clients
contact the Fusion Manager. (To force this contact, restart StoreAll software services on the clients,
reboot the clients, or execute ibrix_lwmount -a or ibrix_lwhost --a.) When contacted,
the Fusion Manager informs the clients about commands that were executed on host groups to
which they belong. The clients then use this information to perform the operation.
You can also use host groups to perform different operations on different sets of clients. To do this,
create a host group tree that includes the necessary host groups. You can then assign the clients
manually, or the Fusion Manager can automatically perform the assignment when you register a
StoreAll client, based on the client's cluster subnet. To use automatic assignment, create a domain
rule that specifies the cluster subnet for the host group.

Creating a host group tree

The clients host group is the root element of the host group tree. Each host group in a tree can
have only one parent, but a parent can have multiple children. In a host group tree, operations
performed on lower-level nodes take precedence over operations performed on higher-level nodes.
This means that you can effectively establish global client settings that you can override for specific
clients.
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