Acer SmartRAID V Bedienungsanleitung PDF herunterladen (Seite 131)

6-19

Storage Manager

Predictive caching is a feature of SmartRAID V controllers that attempts

to reduce average disk access time by determining when the host is

requesting data that it read previously and reading in additional sequential

data before it is actually requested.

This feature can provide enhanced performance when you have a host

with 20 or more users who are frequently accessing large, individual

sequential files. Unless your configuration is similar to this, you will not

see any benefit from using Predictive Cache and using it will adversely

affect overall controller performance. For additional information about

predictive caching, see Predictive Caching Algorithms in Chapter 7.

Array Groups

The tool bar at the top of the Logical Configuration View window contains

Create Array Group, Expand Array Group (Windows NT only) and Delete

Array Group buttons. The Expand Array Group button allows you to add

drives to an existing array and dynamically resize the logical drive.

SmartRAID V controllers can implement any combination of RAID level 0,

1 or 5 disk arrays. RAID 0 arrays can be any combination of individual

drives. RAID 1 arrays are composed of two drives. RAID 5 arrays must

contain at least three drives. One or more arrays of the same RAID level

can be combined into a Parity Group. (This is also referred to as RAID 0+1

for multiple RAID 1 arrays or RAID 0+5 for multiple RAID 5 arrays.) The

drives in a Parity Group appear as a single Logical Storage Unit (LSU) to

the host computer.

NOTE On SmartRAID V controllers, all drives in an array must be

attached to the same controller. For controllers with drives on

multiple SCSI bus channels, arrays are built using the drives

in the order in which they were selected regardless of the bus to

which the drive is attached.

This behavior can be used to create fault-tolerant SCSI bus

configurations using pairs of drives on alternate channels in a

RAID 1 or RAID 0+1 array or with drives distributed across all

three channels for a RAID 5 or RAID 0+5 array.

1 2 ... 126 127 128 129 130 131 132 133 134 135 136 ... 255 256

Keine Kommentare

Acer SmartRAID V Bedienungsanleitung Seite 131