Support For Raid Storage Configurations; Error Correction And Parity Checking - Sun Microsystems Netra 440 Product Overview

Support for RAID Storage
Configurations
By attaching one or more external storage devices to the Netra 440 server, you can
use a redundant array of independent drives (RAID) software application such as
Solstice DiskSuite™ or VERITAS Volume Manager to configure system drive storage
in a variety of different RAID levels. Configuration options include RAID 0
(striping), RAID 1 (mirroring), RAID 0+1 (striping plus mirroring), RAID 1+0
(mirroring plus striping), and RAID 5 (striping with interleaved parity). You choose
the appropriate RAID configuration based on the price, performance, reliability, and
availability goals for your system. You can also configure one or more hard drives to
serve as "hot spares" to fill in automatically in the event of a hard drive failure.
In addition to software RAID configurations, you can set up a hardware RAID 1
(mirroring) configuration for any pair of internal hard drives using the on-board
Ultra-4 SCSI controller, providing a high-performance solution for hard drive
mirroring.
For more information, refer to the Netra 440 Server System Administration Guide (817-
3884-xx).

Error Correction and Parity Checking

DIMMs employ error-correcting code (ECC) to ensure high levels of data integrity.
The system reports and logs correctable ECC errors. (A correctable ECC error is any
single-bit error in a 128-bit field.) Such errors are corrected as soon as they are
detected. The ECC implementation can also detect double-bit errors in the same
128-bit field and multiple-bit errors in the same nibble (4 bits). In addition to
providing ECC protection for data, parity protection is also used on the PCI and
UltraSCSI buses, and in the UltraSPARC IIIi CPU internal caches.
Chapter 2 Reliability, Availability, and Serviceability Features 39