5.5 HP StorageWorks X9300 Network Storage Gateway Administrator Guide (AW539-96007, March 2011)

7 Creating hostgroups for X9000 clients
A hostgroup is a named set of X9000 clients. Hostgroups provide a convenient way to centrally
manage clients using the management console. You can put different sets of clients into hostgroups
and then perform the following operations on all members of the group:
• Create and delete mountpoints
• Mount file systems
• Prefer a network interface
• Tune host parameters
• Set allocation policies
Hostgroups 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.
How hostgroups work
In the simplest case, the hostgroups functionality allows you to perform an allowed operation on all
X9000 clients by executing a management console command on the default clients hostgroup via
either the CLI or the GUI. The clients hostgroup includes all X9000 clients configured in the cluster.
NOTE:
The command intention is stored on the management console until the next time the clients contact
the management console. (To force this contact, restart X9000 Software services on the clients, reboot
them, or execute ibrix_lwmount -a or ibrix_lwhost --a.) When contacted, the management
console informs the clients about commands that were executed on hostgroups to which they belong.
The clients then use this information to perform the operation.
You can also use hostgroups to perform different operations on different sets of clients. To do this,
you will need to create a hostgroup tree that includes the necessary hostgroups. You can then assign
the clients manually, or the management console can automatically perform the assignment when you
register an X9000 client, based on the client's cluster subnet. To use automatic assignment, you will
need to create a domain rule that specifies the cluster subnet for the hostgroup.
Creating a hostgroup tree
The clients hostgroup is the root element of the hostgroup tree. Each hostgroup in a tree can have
exactly one parent, and a parent can have multiple children, as shown in the following diagram). In
a hostgroup 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.
For example, suppose that you want all clients to be able to mount file system ifs1 and to implement
a set of host tunings denoted as Tuning 1, but you want to override these global settings for certain
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