Storage Capacity Per Path - HP XP1024 Operating System Configuration Manual

Storage capacity per path

Installation
In Command View XP AE, LUN mapping includes:
• Configuring ports
• Creating storage groups
• Mapping volumes and WWN/host access permissions to the
storage groups
For details see LUN Configuration and Security Manager User's Guide or
Command View XP Advanced Edition Device Manager Web Client User's
Guide. Note the LUNS and their ports, WWNs, nicknames, and LDEVs for
later use in verifying host and device configuration.
An important difference between MPE/iX and other operating systems
(such as HP-UX) is the determination of disk capacity on a path. MPE/iX is
very sensitive to spindle count (LUNs) per path. If this count exceeds 16
per bus or path, performance problems may result.
To determine the available storage capacity in a path, subtract required
system and application I/O space from the total disk capacity and divide the
result by the spindle count (number of LUNs) in the path.
If performance information isn't available, create a configuration similar to
the installation you had before migrating to the XP array, but be sure not to
exceed 16 LUNs per path. Exceeding this number may cause MPE/iX to
issue more I/O requests than the XP array can service.
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