Huawei OceanStor V3 Series Features Manual page 113

OceanStor V3 Series
Remote Replication Feature Guide for Block
Parameter
Replication Mode
Recovery Policy
Primary Resource Data
Status
Issue 06 (2018-01-30)
Description
Mode of the data replication. The values include:
l Synchronous: When data is written on a primary
resource, the write request is also sent to the secondary
resource. Only after the data is written on both the
primary and secondary resources successfully, does the
host receive a successful data write message.
Synchronous mode ensures that the data on the primary
resource and secondary resource synchronizes in real-
time.
l Asynchronous: When data is written on a primary
resource successfully, the host receives a successful data
write message. In the meanwhile, the primary site
records the data difference between the written data and
the secondary resource. In the data synchronization later,
only the different data the primary site records are
synchronized to the secondary site, reducing the write
latency of application server to the minimum.
After the remote replication internal I/O error is rectified or
the replication link is up, the remote replication pair
automatically synchronizes data or not. The values include:
l Manual: The pair enters the To be recovered state. You
need to manually synchronize the data from the primary
resource to the secondary resource in the pair.
l Automatic: The pair enters the Synchronizing state.
The system will automatically synchronize data from the
primary resource to the secondary resource in the pair.
Status of data on the primary resources. The values include:
l Synchronized: only applies to synchronous remote
replication to indicate that the data synchronization of
primary and secondary resources has been completed. In
the asynchronous remote replication, after data
synchronization of primary and secondary resources has
been completed, the data status of the primary resource
is Consistent.
l Consistent: data status of the primary resource. In
normal states, it is Consistent.
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6 Managing Remote Replication
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