Glossary, Continued

SAF-TE

SCSI Accessed Fault-Tolerant Enclosure. An industry protocol for managing RAID enclosures and

 

reporting enclosure environmental information.

SCSI

(Small Computer System Interface) A processor-independent standard for system-level interfacing

 

between a computer and intelligent devices, including hard disks, floppy disks, CD-ROM, printers,

 

scanners, etc. SCSI can connect up to 7 devices to a single adapter (or host adapter) on the

 

computer's bus. SCSI transfers eight or 16 bits in parallel and can operate in either asynchronous

 

or synchronous modes. The synchronous transfer rate is up to 40 MB/s. SCSI connections

 

normally use single ended drivers, as opposed to differential drivers. The original standard is now

 

called SCSI-1 to distinguish it from SCSI-2 and SCSI-3, which include specifications of Wide

 

SCSI (a 16-bit bus) and Fast SCSI (10 MB/s transfer).

SCSI Channel

MegaRAID controls the disk drives via SCSI-2 buses (channels) over which the system transfers

 

data in either Fast and Wide or Ultra SCSI mode. Each adapter can control up to three SCSI

 

channels.

Service Provider The Service Provider, (SP), is a program that resides in the desktop system or server and is responsible for all DMI activities. This layer collects management information from products (whether system hardware, peripherals or software) stores that information in the DMI’s database and passes it to management applications as requested.

SMARTer

Self-Monitoring, Analysis, and Reporting Technology with Error Recovery. An industry standard

 

protocol for reporting server system information. Self-Monitoring, Analysis and Reporting

 

Technology for disk drives is a specification designed to offer an early warning for some disk drive

 

failures. These failures are predicted based upon actual performance degradation of drive

 

components that are then reported through a graphical interface.

SNMP

Simple Network Management Protocol is the most widely used protocol for communication

 

management information between the managed elements of a network and a network manager. It

 

focuses primarily on the network backbone. The Internet standard protocol developed to manage

 

nodes on an Internet Protocol (IP) network.

Spanning

Array spanning by a logical drive combines storage space in two arrays of disk drives into a single,

 

contiguous storage space in a logical drive. MegaRAID logical drives can span consecutively

 

numbered arrays that each consist of the same number of disk drives. Array spanning promotes

 

RAID levels 1, 3, and 5 to RAID levels 10, 30, and 50, respectively. See also Disk Spanning and

 

Spanning.

Spare

A hard drive available to back up the data of other drives.

Stripe Size

The amount of data contiguously written to each disk. You can specify stripe sizes of 2 KB, 4 KB,

 

8 KB, 16 KB, 32 KB, 64 KB, and 128 KB for each logical drive. For best performance, choose a

 

stripe size equal to or smaller than the block size used by the host computer.

 

Cont’d

134MegaRAID Enterprise 1600 Hardware Guide