Справочник Пользователя для IBM Ultra320

IBM

Chapter

6.

Using

Disk

Arrays

This

chapter

provides

information

about

using

the

RAID-related

features

of

this

adapter.

The

following

tasks

are

beyond

the

scope

of

this

installation

guide

and

are

usually

performed

by

system

administrators.

v

To

use

the

RAID-related

features

of

the

hardware,

disk

arrays

must

be

created

first.

v

AIX

and

Linux

use

and

manage

the

disk

array

in

the

same

way

as

it

would

a

single

non-RAID

disk.

v

For

optimum

performance,

distribute

the

hard

disk

drives

equally

across

the

available

channels.

Using

AIX

For

an

overview

of

RAID

and

detailed

procedures,

refer

to

the

PCI-X

SCSI

RAID

Controller

Reference

Guide

for

AIX,

order

number

SA23-1323.

v

Disk

drives

previously

installed

in

this

system

probably

have

512

bytes/sector.

v

To

use

the

drives

in

disk

arrays

with

this

adapter,

the

disk

drives

must

be

prepared

by

formatting

them

to

522

bytes/sector.

v

Disk

drives

in

512

bytes/sector

format

may

continue

to

be

used

as

standalone

disks

(that

is,

not

part

of

a

disk

array)

on

this

RAID

adapter.

Additionally,

drives

formatted

to

522

bytes/sector

may

be

reformatted

to

512

bytes/sector

at

a

later

time

if

desired

for

compatibility

with

previous

adapters.

v

Formatting

of

drives

to

522

bytes/sector

and

the

creation

of

disk

arrays

may

require

that

data

previously

written

on

the

drives

be

saved

and

restored

after

the

the

disk

arrays

are

created.

v

If

a

disk

array

is

to

be

used

as

the

boot

device,

it

may

be

required

to

prepare

the

disks

by

booting

from

the

Diagnostic

CD

and

creating

the

disk

array

before

installing

AIX.

You

might

want

to

perform

this

procedure

when

the

original

boot

drive

is

to

be

used

as

part

of

a

disk

array.

Using

Linux

For

an

overview

of

RAID

and

detailed

procedures,

refer

to

the

PCI-X

SCSI

RAID

Controller

Reference

Guide

for

Linux,

order

number

SA23-1327.

v

Disk

drives

previously

installed

in

this

system

are

probably

JBOD

drives.

JBOD

drives

are

formatted

to

512

bytes/sector.

v

To

use

the

drives

in

disk

arrays

with

this

adapter,

the

disk

drives

must

be

prepared

by

formatting

them

to

522

bytes/sector.

v

Disk

drives

in

512

bytes/sector

format

may

continue

to

be

used

as

standalone

disks

(that

is,

not

part

of

a

disk

array)

on

this

RAID

adapter.

Additionally,

drives

formatted

to

522

bytes/sector

for

advanced

function

may

be

reformatted

to

512

bytes/sector

at

a

later

time

if

desired

for

compatibility

with

previous

adapters.

v

Formatting

of

drives

to

522

bytes/sector

for

advanced

function

and

the

creation

of

disk

arrays

may

require

that

data

previously

written

on

the

drives

be

saved

and

restored

after

the

disk

arrays

are

created.

v

If

a

disk

array

is

to

be

used

as

the

boot

device,

it

may

be

required

to

prepare

the

disks

by

booting

into

rescue

mode

from

the

Linux

CD

first.

If

your

Linux

distribution

does

not

provide

this

feature,

the

Diagnostic

CD

may

be

used.

You

might

want

to

perform

this

procedure

when

the

original

boot

drive

is

to

be

used

as

part

of

a

disk

array.

13