HP XP Racks - Manual (Page 164)

7 Managing logical volumes
After provisioning your system, you can begin to manage open-system logical volumes. Managing
logical volumes includes tasks such as configuring hosts and ports, configuring LU paths, setting
LUN security on ports, and setting up fibre channel authentication.
LUN Manager is required to manage logical volumes.
LUN Manager overview
LUN Manager operations
The HP XP7 Storage can be connected to open-system server hosts of different platforms (for
example, UNIX servers and PC servers). To configure a system that includes open-system hosts and
a HP XP7 Storage, use LUN Manager to configure logical volumes and ports.
One of the important tasks when configuring logical volumes is to define I/O paths from hosts to
logical volumes. When paths are defined, the hosts can send commands and data to the logical
volumes and also can receive data from the logical volumes.
After the system begins operating, you might need to modify the system configuration. For example,
if hosts or disks are added, you will need to add new I/O paths. You can modify the system
configuration with LUN Manager when the system is running. You do not need to restart the system
when modifying the system configuration.
Fibre channel operations
After open-system hosts and the storage system are physically connected by cables, hubs, and so
on, use LUN Manager to establish I/O paths between the hosts and the logical volumes. This
defines which host can access which logical volume. Logical volumes that can be accessed by
open-system hosts are referred to as logical units (LUs). The paths between the open-system hosts
and the LUs are referred to as LU paths.
Before defining LU paths, you must classify server hosts by host groups. For example, if Linux hosts
and Windows hosts are connected to the storage system, you must create one host group for the
Linux hosts and another host group for the Windows hosts. Then, you must register the host bus
adapters of the Linux hosts in the Linux host group. You must also register the host bus adapters of
the Windows hosts in the windows host group.
A host group can contain only those hosts that are connected to the same port, and cannot contain
hosts that are connected to different ports. For example, if two Windows hosts are connected to
port 1A and three Windows hosts are connected to port 1B, you cannot register all five Windows
hosts in one host group. You must register the first two Windows hosts in one host group, and then
register the remaining three Windows hosts in another host group.
After server hosts are classified into host groups, you associate the host groups with logical volumes.
The following figure illustrates LU paths configuration in a fibre channel environment. The figure
shows host group hg-lnx associated with three logical volumes (00:00:00, 00:00:01, and
00:00:02). LU paths are defined between the two hosts in the hg-lnx group and the three logical
volumes.
164 Managing logical volumes