HP-UX System Administrator's Guide: Overview

File System Type
Your choice of file system type can also affect the efficiency of accessing your data. The
VERITAS File System (VxFS) is generally faster than using the HFS file system.
Establishing Multiple Paths to a Device (for efficiency)
Beginning with HP-UX 11i version 3, HP-UX 11i supports device multipathing, a new
technology that associates device files with devices by using unique device IDs rather
than the hardware path to the devices. This means that a single device file can represent
multiple hardware paths to a given device which, when combined with hardware that has
multiple ports (supporting multiple physical connections), yields not only redundant
paths to the device, but greater I/O bandwidth. HP-UX 11i version 3 can automatically
load balance between multiple physical connections to a device, improving I/O
efficiency.
For more information on device multipathing, see “How Storage is Addressed”
(page 59).
Disk Mirroring (for performance)
Though the topic of disk mirroring is more of a data redundancy topic, there are
performance reasons for mirroring. If you use a RAID 1 (mirroring) disk configuration
in an environment more focused on reading data from the disks rather than writing
data to the disks in the mirror, you can significantly speed up data input because
subsequent disk blocks can be retrieved in parallel from alternating devices. For
additional benefits of using RAID 1 configurations, see “Disk Mirroring”.
Storage and Data Redundancy
The value of most data in the information age ranges from important to critical. The
importance of data redundancy is directly proportional to the importance of the data
being protected.
Data redundancy can take many forms but in every form multiple copies of your data
exist so that if the primary copy of the data is damaged or destroyed another copy of
those data can be used to continue your operations.
When choosing a data redundancy technology consider the following:
• How quickly do you need to recover from data loss?
• How easy is it to switch over to the alternate copy of your data should the primary
become unusable?
• Do you need off site copies of your data?
• How often do the data change?
56 Major Components of HP-UX