Mylex AcceleRAID 170, Installation Manual

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G-18 AcceleRAID 170 Installation Guide
Offline: A SCSI disk drive is in a “offline” state if it is not present, if it is
present but not powered on, or if it failed to operate properly and was
“offline” by the controller. When the controller detects a failure on a disk, it
“kills” that disk by changing its state to “offline.” An “offline” SCSI drive
can also be present and powered on, but a SCSI drive in a “offline” state does
not participate in any I/O activity; no commands are issued to dead drives.
Rebuild: A SCSI disk drive is in a “rebuild” state while it is in the process of
being rebuilt. During this process, data is regenerated and written to the disk
drive. This state is also referred to as “Write-Only” (WRO).
SCSI Interrupt Steering Logic (SISL)
Architecture that allows a RAID controller, such as AcceleRAID 150, 200 or
250, to implement RAID on a system board-embedded SCSI bus or a set of
SCSI busses.
SDRAM
Synchronous Dynamic Random Access Memory, a form of dynamic random
access memory (DRAM) that can be coordinated or synchronized to the
clock speed of the computer.
Segment Size
See Cache Line Size.
Sequential I/O
A type of read and write operation where entire blocks of data are accessed
one after another in sequence, as opposed to randomly.
Server
A computer program that provides and manages services to other computer
programs on the same or other computers. The computer that a server
program runs in is also frequently referred to as a server.
SES
SCSI Enclosure Services, a standard for SCSI access to services within an
enclosure containing one or more SCSI devices. For disk drives, power
supplies, cooling elements, and temperature sensors, the actions performed
are the same as for SAF-TE monitoring. If a UPS is connected to any
SES-monitored enclosures, and an AC failure or two minute warning is