PRIMECLUSTER Global Disk Services Configuration and Administration Guide 4.1 (Solaris(TM) Operating System)

2.2 Disk Class

Disk class is the largest unit managed by GDS. Disk class may be referred to as "class".

In order to manage disk units (physical disks) with GDS, you must first register the physical disk with a certain class. A class is like a container that holds multiple disks for management.

By using the registered physical disks, GDS creates and manages objects such as disks, groups, volumes, and slices within a class.

Objects including classes can be named as the user wants. Respective names must be unique throughout the entire system.

When multiple single nodes on which classes with the same name exist are changed over to a cluster system through installation of the cluster control facility, the duplicate class names come to exist in the cluster system. For details, see "Changing Over from Single Nodes to a Cluster System."

 

Attributes

A class has the following attributes.

Name

This attribute identifies the class within a system.

Type

This attribute specifies the type of class. You can set to one of the following.

Root

Object managed in a class that is available only to its own node. "Root" type can manage system disk, while "local" type cannot.

Local

Object managed in a class that is available only to its own node.

Shared

Object managed in a class that is available to more than one node.

Scope

This attribute indicates a group of nodes on which objects in the class are available.

Hot Spare

This attribute indicates the hot spare operation mode. Either of the following values can be set.

on

Hot spare is enabled.

off

Hot spare is disabled. Automatic connections of spare disks are prevented.

Hot Spare Mode

This attribute indicates the spare disk selection mode of automatic connection for hot spare. One of the following values can be set.

External

If an I/O error occurs in a disk of a disk array unit, this method selects a spare disk that belongs to a different disk case from that of the failed disk.
If an I/O error occurs in a disk irrelevant to a disk array unit (such as an internal disk), it selects a spare disk that is connected to a different controller from that of the failed disk. When no applicable unconnected spare disk is found there, a spare disk that belongs to the same disk case or is connected to the same controller as that of the disk with the I/O error, is selected.

Internal

If an I/O error occurs in a disk of a disk array unit, this method selects a spare disk that belongs to the same disk case as that of the failed disk.
If an I/O error occurs in a disk irrelevant to a disk array unit (such as an internal disk), it selects a spare disk that is connected to the same controller as that of the failed disk. When no applicable unconnected spare disk is found there, spare disk automatic connection is not performed.

 

Operation

The following operations are available for classes.

Create

Registering a disk with the sdxdisk -M command and specifying a new class name will automatically create a new class. For details on GDS Management View, see "Class Configuration."

Delete

Deleting the last registered disk from a class using the sdxdisk -R command will automatically delete the class. You can also delete the classes with the sdxclass -R command or the sdxconfig Remove command. For details on GDS Management View, see "Removing a Class."

Status Display

Class status can be displayed with the sdxinfo command. For details on GDS Management View, see "Viewing Configurations and Monitoring Statuses."

Change Attributes

Class attribute values can be changed with the sdxattr -C command. For details on GDS Management View, see "Class Configuration."

Recover

Closed classes can be recovered with the sdxfix -C command. The operation from GDS Management View is unsupported.

Backup

The object configuration within a class can be backed up in configuration table format to a configuration file with the sdxconfig Backup command. The operation from GDS Management View is unsupported.

Restore

The object configuration of a class can be restored according to the configuration table in the configuration file with the sdxconfig Restore command. The operation from GDS Management View is unsupported.

Convert

A configuration table in a configuration file can be converted with the sdxconfig Convert command in order to restore the object configuration of the class in environment other than the original. The operation from GDS Management View is unsupported.

 

Status

A class can have the following status.

Closed

All objects within a class are unavailable for reference. For details, see "Class status abnormality."

 

Reference

There are the following points of concern for classes.

Rules

Object Name

Number of Classes

Important Points

Physical Disk Driver

Managing System Disks

Booting from a CD-ROM Device

System Disk Mirroring

Operation in Cluster System

Changing Over from Single Nodes to a Cluster System

Configuration Tables

 

[Figure: Disk Class]