How Do I Use The Secondary Lun In A Remote Replication Task; Why Information About The Primary Device And The Secondary Device In A Remote Replication Task Cannot Be Updated In Real Time - Huawei OceanStor V3 Series Features Manual

OceanStor V3 Series
Remote Replication Feature Guide for Block
9.2 How Do I Use the Secondary LUN in a Remote
Replication Task
Question

How do I use the secondary LUN in a remote replication task?

Answer
The primary LUN and the secondary LUN in a remote replication form a pair, and the
secondary LUN stores a data duplicate for the primary LUN.
l
l
9.3 Why Information About the Primary Device and the
Secondary Device in a Remote Replication Task Cannot
Be Updated In Real Time
Question
Why information about the primary device and the secondary device in a remote replication
task cannot be updated in real time?
Answer
The symptoms and reasons are as follows:
l
l
Issue 06 (2018-01-30)
In normal cases, the secondary LUN cannot be accessed by a host. To enable a host to
access data on the secondary LUN, you can create a snapshot for the secondary LUN and
map the snapshot to the host.
When the primary LUN fails and causes service interruption, you must perform a
primary/secondary switchover to change the secondary LUN to the primary LUN, and
then map the new primary LUN to the host.
Symptom 1: After data synchronization between the primary LUN and the secondary
LUN is initiated, the secondary device does not display the synchronization progress in
real time.
To display the synchronization progress in real time during data synchronization, the
secondary device must send a query task to the primary device. This affects system
performance.
Symptom 2: After the name of the primary device is changed, the name in the remote
replication is not updated in real time.
The name of the primary device in a remote replication task is obtained by invoking the
interface of the system management module rather than using the remote replication
module. Therefore, after the device name is changed, the remote replication cannot
detect the change. In this case, you can refresh the information manually or log in to the
DeviceManager again. Then, the name of the primary device will be updated.
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
9 FAQs
158