Sun Fire V445 Server Administration Guide - SCN Research

(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 disk drives to serve as “hot spares” to fill in
automatically in the event of a disk drive failure.
In addition to software RAID configurations, you can set up a hardware RAID 1
(mirroring) configuration for any pair of internal disk drives using the SAS
controller, providing a high-performance solution for disk drive mirroring.
For more information, see the following:
■ “About Volume Management Software” on page 112
■ “About RAID Technology” on page 114
■ “Creating a Hardware Disk Mirror” on page 118
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. ECC detection and
correction for DRAM is present in the 1 Mbyte on-chip ecache SRAM of the
UltraSPARC-IIIi processor.
About the ALOM System Controller
Command Prompt
The ALOM system controller supports a total of five concurrent sessions per server:
four connections available through the network management port and one
connection through the serial management port.
Note – Some of the ALOM system controller commands are also available through
the Solaris scadm utility. For more information, see the Sun Advanced Lights Out
Manager (ALOM) Online Help.
Chapter 5 Managing RAS Features and System Firmware 97