Are Hot Fix Drives Needed; Intel Raid Controller Hardware Features; Architecture Features (Hw); Raid Level, Hard Disk Drives, And Usable Storage Capacity - Intel SRCU31A - Server RAID U3-1A Controller User Manual

Table 2.

RAID Level, Hard Disk Drives, and Usable Storage Capacity

RAID Level
RAID 0
RAID 1
RAID 4
RAID 5
RAID 10
* Each hard disk drive is assumed to have 1 GB capacity.

Are Hot Fix Drives Needed?

Assume that one of the hard disk drives of the RAID 5 disk array fails (Hot Fix drives are available
with RAID 1, 4, 5, and 10 arrays). The disk array is without redundancy. Time Without
Redundancy (TWR) starts to run. Any unnecessary prolongation of the TWR (the time required to
get a replacement drive, or because you did not immediately recognize the failure) increases the
risk of data loss that will occur should a second drive fail. Therefore, redundancy should be
restored as soon as possible and in an automated manner. Integrating a Hot Fix drive (also referred
to as hot spare) as an immediately available and auto-replacing drive is the most effective way to
keep the TWR as short as possible. Only a Hot Fix drive can ensure optimal disk array security and
constant data availability.
Using a Hot Fix drive is not compulsory. If you control the disk array at regular intervals and
immediately replace a defective drive (by shutting down the system or hot-plugging), you can
operate the system without a Hot Fix drive.

Intel RAID Controller Hardware Features

This section provides a summary of the key features, configuration options, and support interface
technology supported by the Intel RAID Controller SRCU31.

Architecture Features (HW)

Table 3.

Hardware Architecture

Component
CPU
Memory/Cache
Cache
Firmware
PCI
Array Interface to Host
PCI Signaling
Getting Started
Available Available
Capacity with Capacity with
2 Hard Disk 3 Hard Disk
Drives* Drives*
2 GB 3 GB
1 GB 1 GB
NA 2 GB
NA 2 GB
NA NA
Features
®
Intel i960
controller features hardware XOR support for high speed RAID 5
parity calculations.
3.3v, unbuffered PC100, ECC, SDRAM DIMM expandable to 32, 64,
or 128 MB.
Downstream Write Through, Full and Sequential
Write-Back - Selectable per volume.
ROM Type, Flash EEPROM, 2 Mb x 8 (flashable).
Transfer Rate: 264 MB/sec.
Interface to Host PCI 2.2.
Capable of being used in a 5 or 3.3 volt slot.
Available
Capacity with
4 Hard Disk
Drives*
4 GB
1 GB
3 GB
3 GB
2 GB
®
RN I/O Processor, 100 MHz, RISC 32-bit core. This
Available
Capacity with
5 Hard Disk
Drives*
5 GB
1 GB
4 GB
4 GB
NA
29