HP XP Array Manager Software - Manual (Page 17)

If a hardware failure (such as a CHA failure) occurs, there is a chance that some LU paths will be
disabled and some I/O operations stopped. To avoid such a situation, the system administrator can
define alternate LU paths; if one LU path fails, the alternate path takes over the host I/O.
For instructions on how to define LU paths, see “
Defining Fibre Channel LU Paths ” on page 33. For instruc­
tions on how to change LU path settings, see “ Changing the Fibre Channel LU Path Settings ” on page 59.
For instructions on how to define alternate paths, see “ Defining and Viewing Alternate Paths ” on page 79.
Notes:
• In a Fibre Channel environment, up to 2,048 LU paths can be defined for one host group. Up to
2,048 LU paths can be defined for one port.
• You cannot define any LU path to volumes reserved by HP StorageWorks XP Auto LUN Software.
• Up to 255 host groups can be created for one Fibre Channel port.
• You cannot define any LU path to journal volumes.
• You cannot define any LU path to pool volumes.
• You cannot define any LU path to System Disk volumes.
Configuring LUN Security
To protect mission-critical data in your storage system from illegal access, you must apply security policies
to logical volumes. LUN Manager lets you enable LUN security on ports to safeguard LUs from illegal
access.
Note : If a port has the External attribute, you cannot apply LUN security to the port.
If LUN security is enabled, host groups affect which host can access which LUs. Hosts can only access
LUs associated with the host group to which the hosts belong. The hosts cannot access LUs associated
with the other host groups. For example, hosts in the hp-ux host group cannot access LUs associated
with the windows host group. Also, hosts in the windows host group cannot access LUs associated with
the hp-ux host group.
In
Figure 2 on page 17, LUN security is enabled on port CL1-A. The two hosts in the hg-lnx host group
can only access the three LUs 00:00:00, 00:00:01, and 00:00:02. The two hosts in the hg-hpux host
group can only access the two LUs 00:02:01 and 00:02:02. The two hosts in the hg-solar host group can
only access the two LUs 00:01:05 and 00:01:06.
Figure 2 Enabling LUN Security
Usually, you do not need to disable LUN security on ports. If LUN security is disabled on a port, the
connected hosts will only be able to access LUs associated with host group 0 (zero), and will be unable to
access LUs associated with any other host group.
XP24000 LUN Manager User's Guide 17