Installation guide

Fault Tolerant Design
1-8 Fault Tolerant System Administration (R1004H) HP-UX version 11.00.03
board resources (for example, SCSI ports on I/O controllers) or software
configuration of board resources (for example, using RNI to configure dual
Ethernet ports).
■ buses—In Continuum Series 400/400-CO systems, the suitcases and PCI
bridge cards are cross-wired on the main bus to provide fault tolerance. The
combination of error detection, retry logic, and bus switching ensures that all
bus transactions are fault tolerant.
■ disks—The LVM utilities let you create mirrored disks and logical data
volumes, which you can configure in various ways to protect data.
■ power supplies—All Continuum systems support powerfail logic to ‘ride
through’ short power outages or gracefully shut down during longer power
outages. Continuum Series 400/400-CO systems include several, and in some
cases redundant, power supplies for various system components (suitcase,
disk, PCI bus, and alarm control unit).
■ fans—Continuum Series 400/400-CO systems include multiple multispeed
cabinet and suitcase fans to control temperature. All Continuum systems
support environmental-monitoring logic that identifies fan faults and adjusts
fans speed as necessary to maintain proper cooling.
Solo Components
Solo components do not have backup partners. If a solo component fails, services
supported by that component are no longer available and operation could be
interrupted. The components that operate in a solo fashion are as follows:
■ I/O adapter cards—I/O adapter cards function as solo components unless
they are dual-initiated or software-configured as a pair.
■ PCI bridge cards—Each PCI bridge card supports a separate card-cage. PCI
bridge cards cannot be duplexed; if a PCI bridge card fails, support is lost for
all I/O adapter cards in that card-cage.
■ tape and CD-ROM drives—Tape and CD-ROM drives are not paired, so tape
and CD-ROM operations that fail must be repeated.
■ simplex disk volumes—You can configure a disk as a simplex volume if you
do not need to protect your data and you want to maximize storage capacity.
However, this practice is not recommended.