The External Volumes list provides the following information:

Item

Description

 

 

ExG

External volume group number and sequential number

 

assigned to each volume in the external volume group.

 

This appears in the format of external volume group

 

number - sequential number of volume in

 

the group. The sequential numbers of volumes in the

 

group are automatically assigned by XP External Storage

 

when the external volumes are mapped.

 

 

LDEV

LDKC:CU:LDEV number that is assigned to the external

 

volume. When multiple LDEVs are created in the external

 

volume, the top LDEV number appears, and [...] appears

 

at the end of the number.

 

 

Characteristic1

Identification number of the external volume.

 

 

Device

Name of the storage system that is reported to the host by

 

the external volume. The displayed items differs depending

 

on the vendor of the storage system.

 

 

Capacity (blocks)

Capacity, in blocks, of the external volume.

 

 

Cache Mode

Indicates whether the write data from the host to the

 

external storage system is propagated synchronously

 

(Disable) or asynchronously (Enable). Data that is not written

 

by the host (for example, data written by XP Business Copy)

 

is asynchronously destaged to the external storage system

 

regardless of the Cache Mode setting.

 

 

Inflow Control

Indicates whether the writing operation to the cache

 

memory is stopped (Enable) or continued (Disable) when

 

the writing operation to the external volume is impossible.

 

 

Path Mode

Indicates how the cross-subsystem paths work. The modes

 

of the cross-subsystem path are as follows:

 

• Single: Only the cross-subsystem path with the highest

 

 

priority (primary path) is used to execute the I/O to the

 

 

external volume. When an error occurred in the primary

 

 

path, the path with the second highest priority is used.

 

• Multi: All of the cross-subsystem paths are used at the

 

 

same time. The multiple paths are used to execute the

 

 

I/Os to the external volume distributing the work load.

 

• APLB: All of the cross-subsystem paths are used at the

 

 

same time. The multiple paths are used to execute the

 

 

I/Os to the external volume distributing the work load.

 

 

However, the paths are not used when the paths are

 

 

connected to ports in the Passive status.

 

 

Ext. VOL Info

Information about the external volume.

 

An asterisk (*) appears when the external volume is a SATA

 

drive of the following storage systems. Usage of SATA

 

drives differs depending on storage systems, and therefore

 

SATA drives should be used accordingly.

 

• USP V/USP VM storage system

 

•

AMS/WMS storage system

 

•

SMS storage system

 

• Thunder 9500V series storage system

 

A dollar sign ($) appears when the external volume is an

 

SSD drive of the USP V/USP VM storage system. Usage

 

of SSD drives differs depending on storage systems, and

 

therefore SSD drives should be used accordingly.

 

 

 

52 Using the XP External Storage GUI