9.13 How Can I Solve the Problem if the Logical
Bandwidth and the Replication Link Bandwidth Are Not
the Same in Asynchronous Remote Replication
Question
How can I solve the problem if the logical bandwidth and the replication link bandwidth are
not the same in asynchronous remote replication?
Answer
Synchronization can be classified into the following three scenarios based on the types of
primary and secondary LUNs:
l
The primary LUN is a thin LUN not configured with SmartDedupe&SmartCompression
and the secondary LUN is a thin LUN with no space allocated. During the initial
synchronization, data for which space is not allocated on the primary LUN will not be
synchronized to the secondary LUN.
l
The primary LUN is a thick LUN or a thin LUN configured with
SmartDedupe&SmartCompression and the secondary LUN is a thin LUN with no space
allocated. During the initial synchronization, data in the primary LUN is read in
sequence and the consecutive 64 KB all zero data will not be synchronized to the
secondary LUN.
l
In other scenarios except the previous two, during the initial synchronization, the system
reads data in the primary LUN in sequence. The 64 KB all zero data is compressed to 4
KB (16:1), synchronized to the secondary LUN, decompressed to 64 KB, and then
written to the secondary LUN. Other data is written to the secondary LUN in sequence.
The amount of data to be transmitted is reduced to fully tap into bandwidth resources. As a
result, the logical bandwidth and the replication link bandwidth are not the same.
In addition, the logical bandwidth of an asynchronous remote replication task varies greatly
from the replication link bandwidth after link compression is enabled and the performance of
asynchronous remote replication drops sharply. Inline compression automatically compresses
data when data is sent through links and decompresses data when the secondary storage
system receives the data. Inline compression also reduces the amount of data transferred over
a network.
9.14 What Can I Do If the Remote Connection Fails to Be
Created with the TOE Interface Module
Question
What can I do if the remote connection fails to be created with the TOE interface module?
Answer
When a remote device whose type is
Replication
is added, or the iSCSI link is added to the
remote device, if error code
1073804034
occurs or the connection fails to be created, the
OceanStor V3 Series
Remote Replication Feature Guide for Block
9 FAQs
Issue 06 (2018-01-30)
Huawei Proprietary and Confidential
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