Huawei OceanStor 2000 V3 Series Features Manual page 36

OceanStor V3 Series
HyperMetro Feature Guide for File
Read I/O Process
Data on the file systems of both storage arrays is synchronized in real time. If the storage
system in one data center malfunctions, the storage system in the other data center continues
providing host services alone.
Figure 1-4
Figure 1-4 Read I/O process
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Issue 05 (2018-01-30)
NOTE
If the write I/O fails to be written to the local or remote cache, HyperMetro services are
suspended and the storage system in each data center sends an arbitration request to the
quorum server. The storage system that wins the arbitration continues providing services and
the one that fails stops. In the background, the storage system uses the DCL to synchronize
data. Once the data in the local file system is identical to the data in the remote file system,
HyperMetro services are restored.
shows the read I/O process.
Host
5
1
HyperMetro management module
2
4.1
3
Local file
system
Remote storage array
Local storage array
A host applies for read permission from the HyperMetro management module.
NOTE
If the link between the storage arrays in the two data centers is down, the quorum server
determines which storage array continues providing services for hosts.
The HyperMetro management module enables the local storage system to respond to the
read I/O request made by the host.
If the local storage system is operating properly, it returns data to the HyperMetro
management module. The logical ports of the local storage array are activated but the
logical ports of the remote storage array are not activated. The local storage array
provides services for hosts.
If the local storage array is not operating properly, the logical ports of the remote storage
array are activated and the logical ports of the local storage array are deactivated. The
remote storage array provides services for hosts and returns data to the HyperMetro
management module.
The read I/O request made by the host is processed successfully.
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4.2
Remote file
system
1 Feature Description
28