Manage async remote replication pairs
An async remote replication pair maps a local block device to a remote block device for asynchronous data replication between the block devices. You can create, edit, delete, split, and synchronize replication pairs, perform a primary/secondary switchover for a replication pair, enable secondary block device protection, and export information about all replication pairs.
Restrictions and guidelines
A cluster supports a maximum of 256 async remote replication pairs.
The primary and secondary block devices in an async remote replication pair must have the same size.
You cannot edit a replication pair in Invalid or Deleting state.
The delete operation will terminate the replication relationship between the primary and secondary block devices and cannot be revoked.
Create an async remote replication pair
Select Storage Disaster Recovery from the navigation pane.
Click the Async Remote Replication tab.
Click Add.
In the dialog box that opens, select a remote device and click Next.
In the Primary Block Device section, select a disk pool and a data pool. Then, select a primary block device and click Next.
In the Secondary Block Device section, select a disk pool and a data pool. Then, select a secondary block device and click Next.
Configure replication settings as described in "Parameters," and then click Next.
Click Finish.
Edit an async remote replication pair
Select Storage Disaster Recovery from the navigation pane.
Click the Async Remote Replication tab.
Click the
icon for an async remote replication pair.
In the dialog box that opens, edit the parameters as described in "Parameters."
Click OK.
Delete an async remote replication pair
Select Storage Disaster Recovery from the navigation pane.
Click the Async Remote Replication tab.
Click the
icon for an async remote replication pair.
In the dialog box that opens, select an option from the Delete From field.
To delete a replication pair only from the local cluster, select Local Cluster.
To delete a replication pair from both the local and remote clusters, select Local and Remote Clusters.
Click OK.
In the dialog box that opens, click Yes.
View details about an async remote replication pair
Select Storage Disaster Recovery from the navigation pane.
Click the Async Remote Replication tab.
Click the
icon for an async remote replication pair.
Parameters
Create an async remote replication pair
Remote Device section: Provides the remote cluster name, device ID, and description of remote devices.
Primary Block Device section
Disk Pool: Select a disk pool for the primary block device.
Data Pool: Select a data pool for the primary block device.
Block device list: Provides information of block devices.
Name: Block device name.
Size: Block device capacity.
Description: Block device description.
Secondary Block Device section
Disk Pool: Select a disk pool for the secondary block device.
Data Pool: Select a data pool for the secondary block device.
Block device list: Provides information of block devices.
Name: Block device name.
Size: Block device capacity.
Description: Block device description.
Replication Attributes section
Initial Sync: Specifies an initial synchronization policy for the async remote replication pair. Options include the following:
Automatic—The system automatically synchronizes the primary and secondary block devices for data consistency immediately after the replication pair is created.
Manual—Make sure you perform synchronization after the replication pair is created. The pair will stay in Split state until you perform a manual sync.
Skip—Select this option only if you are sure that the primary and secondary block devices have data consistency.
Speed: Specifies a data replication speed. Options include the following:
Low—The speed is equal to or lower than 5 Mbps.
Medium—The speed is equal to or lower than 20 Mbps.
High—The speed is equal to or lower than 70 Mbps.
Ultra—The speed is not limited and depends on the network condition of the cluster.
Restore Mode: Specifies a restore mode for the async remote replication pair. Options include the following:
Auto—After a failure, the system will automatically perform synchronization periodically to recover data from the failure.
Manual—After a failure, the system will not perform an automatic sync. You can manually recover data from More Actions > Sync on the Async Remote Replication tab.
Sync Mode: Specifies a timing policy for scheduled automatic synchronization between the primary and secondary block devices. Options include:
Interval-Based (Timer Starts on Start of Sync)—Timer starts upon the start of this synchronization. The next synchronization automatically starts after the interval timer expires.
Interval-Based (Timer Starts on Completion of Sync)—Timer starts upon the completion of this synchronization. The next synchronization automatically starts after the interval timer expires.
Time-Based—Synchronization starts at the specified time.
Not Configurable—No synchronization policies are set. You can manually perform a synchronization from More Actions > Sync on the Async Remote Replication tab.
Schedule: Specifies an interval or time based on the synchronization mode. Options include the following:
Interval Based—Specifies the interval for synchronization. This option is available when the synchronization mode is Interval-Based (Timer Starts on Start of Sync) or Interval-Based (Timer Starts on Completion of Sync).
Time Based—Specifies the time for synchronization. This option is available when the synchronization mode is Time-Based.
Delete a remote replication pair
Delete From: Select the location from which the remote replication pair is to be deleted.
Local Cluster: Delete the replication pair only from the local cluster. To delete a replication pair from the local cluster, make sure the pair is in Invalid state or disconnect the link to the remote cluster.
Local and Remote Clusters: Delete the replication pair from both the local and remote clusters. To delete a replication pair from the local and remote clusters, make sure the link to the remote cluster is operating correctly and the pair is in Split, To Be Restored, or Abnormally Stopped state.
Ensure Secondary Block Device Data: Set whether to ensure data integrity for the secondary block device. Options include the following:
No—The system will not restore the secondary block device even if the secondary block device data is not integrated. The secondary block device is not available if its data is not integrated. To use the secondary block device, you must manually clear its data.
Yes—The system restores the secondary block device by using the most recent snapshot if the secondary block device data is not integrated. The restoration cannot be interrupted and might be time-consuming. If the initial synchronization has not completed when you delete the pair, the system cannot restore the secondary block device even if you enable this feature. In this case, please manually clear the secondary block device data before you use the block device.
View details about an async remote replication pair
Pair ID: Unique identifier of the async remote replication pair.
Secondary Resource Data State: Whether the data on the secondary block device is complete.
Complete—The primary and secondary block devices have data consistency.
Incomplete—The primary and secondary block devices have inconsistent data. The cause might be unfinished initial synchronization or synchronization interruption.
Sync Started At: Date and time when the most recent synchronization started.
Sync Ended At: Date and time when the most recent synchronization ended.
Last Successful Sync Started At: Date and time when the most recent successful synchronization started.
Role: Role of the cluster for the replication pair.
State: State of the replication pair. Options include:
Normal—The pair is operating correctly.
Synchronizing—The primary and secondary block devices are synchronizing data.
To Be Restored—The pair is operating incorrectly. You can manually perform a synchronization to recover data.
Deleting—When you delete an async remote replication pair, the pair enters Deleting state if the system is restoring a snapshot of the secondary block device. The pair will not be deleted until the snapshot restoration is finished.
Split—The synchronization relationship between the primary and secondary block devices is suspended.
Invalid—The pair enters Invalid state in one of the following situations:
a. Only one of the block devices in a pair is deleted successfully when you delete the pair.
b. After a primary/secondary switchover, both block devices are primary block devices.
c. Failed to recover data from a failure.
Abnormally Stopped—Data synchronization between the primary and secondary block devices is abnormally interrupted.
Health: Health state of the replication pair.
Normal—The replication pair is operating correctly.
Failed—The replication pair has failed. If the state of the replication pair is Abnormally Stopped, synchronization was interrupted or failed to be started because of network or cluster failure. After the network or cluster recovers, the replication pair resumes synchronization. If the state of the replication pair is Invalid, the application pair is unusable. You can only delete it and create a new replication pair.