User's Manual

Chapter 2 System Overview 19
About Reliability, Availability, and
Serviceability Features
Reliability, availability, and serviceability (RAS) are aspects of a system’s design that
affect its ability to operate continuously and to minimize the time necessary to
service the system. Reliability refers to a system’s ability to operate continuously
without failures and to maintain data integrity. System availability refers to the
percentage of time that a system remains accessible and usable. Serviceability relates
to the time it takes to restore a system to service following a system failure. Together,
reliability, availability, and serviceability features provide for near continuous
system operation.
To deliver high levels of reliability, availability and serviceability, the Sun Fire V490
system offers the following features:
■ Hot-pluggable disk drives
■ Redundant, hot-swappable power supplies
■ Environmental monitoring and fault detection
■ Automatic system recovery (ASR) capabilities
■ Multiplexed I/O (MPxIO)
■ Remote “lights out” management capability
■ Hardware watchdog mechanism and externally initiated reset (XIR)
■ Dual-loop enabled FC-AL subsystem
■ Support for disk and network multipathing with automatic failover capability
■ Error correction and parity checking for improved data integrity
Hot-Pluggable and Hot-Swappable Components
Sun Fire V490 hardware is designed to support hot-plugging of internal disk drives
and hot-swapping of power supplies. With the proper software support, you can
install or remove these components while the system is running. Hot-plug and
hot-swap technology significantly increases the system’s serviceability and
availability, by providing the ability to:
■ Increase storage capacity dynamically to handle larger work loads and improve
system performance
■ Replace disk drives and power supplies without service disruption
For additional information about the system’s hot-pluggable and hot-swappable
components—including a discussion of the differences between the two
practices—see “About Hot-Pluggable and Hot-Swappable Components” on page 26.