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For Distributed Consistency Groups in a Dell RecoverPoint environment, the minimum size required for each journal volume is 40 GB.This is the minimum per copy, which can be a single LUN or multiple LUNs that add up to at least 40 GB1.

The size of the journal is determined by the write change rate of what is being replicated and the protection window required per Consistency Group. A general rule of thumb is about 15-20% of the total amount of data being replicated.For example, if a Distributed Consistency Group (DCG) has production server LUNs totaling 500 GB, then the journal per copy would be about 100 GB following this rule1.

It’s important to note that while 40 GB is the minimum, the actual size may need to be larger depending on the specific requirements and write change rate of the environment.The journal size should be sufficient to handle the data changes and provide the necessary protection window1.

RecoverPoint Write Phase:

In the RecoverPoint replication process, the write splitter plays a crucial role in intercepting writes from the host and forwarding them to both the production storage and the RecoverPoint appliances (RPAs).

Write Splitter Functionality:

The write splitter intercepts write I/O requests from the host and splits the I/O to both the production LUN and the RPAs. This ensures that the data is written to both the primary storage and replicated copies.

Acknowledgement Process:

During the write phase, the write splitter must ensure that the data is successfully written to the production LUN before acknowledging the write request back to the host.

This is because the primary concern is ensuring data integrity and confirming that the data is safely stored in the production environment before any replication considerations.

Detailed Workflow:

Step 1: Host issues a write request.

Step 2: The write splitter intercepts the write request.

Step 3: The write splitter forwards the write to the production LUN and the RPAs.

Step 4: The production LUN processes the write and sends an acknowledgement back to the write splitter.

Step 5: Upon receiving the acknowledgement from the production LUN, the write splitter then sends an acknowledgement back to the host.

A screenshot of a recovery program Description automatically generated with medium confidence

To recover a production volume that has become inaccessible due to logical corruption using RecoverPoint’s “Test a Copy and Recover Production” wizard, follow these steps:

Select a snapshot prior to the corruption: Identify and choose the appropriate point-in-time image from the Journal that was taken before the corruption occurred.

Mount the snapshot to a verification host and verify its integrity: Attach the selected snapshot to a non-production host where you can perform checks to ensure the data is consistent and free from corruption.

Unmount the production volume as the Recovery wizard will overwrite it with the recovery data: Ensure that the current production volume is not in use because the recovery process will overwrite the existing data with the data from the snapshot.

Monitor the progress of recovery from the Unisphere ‘Manage Recovery’ wizard: Use Dell EMC’s Unisphere interface to track the recovery process and ensure that the data is being restored correctly.

These steps are based on the standard procedures outlined in Dell RecoverPoint documentation for using the “Test a Copy and Recover Production” wizard to restore volumes to a previous state1.

In a Distributed Consistency Group (DCG) configuration, the primary RPA and secondary RPAs work together to manage a larger data throughput than a single RPA can handle. This is achieved by dividing the workload among multiple RPAs. As a result, there is an increase in traffic observed on the WAN network between the RPAs.This is because the data that is being replicated needs to be transferred over the WAN to ensure that all RPAs have the necessary information to maintain consistency and data protection1.

The process involves:

The primary RPA receives write I/Os from the production environment.

The primary RPA then distributes the data to the secondary RPAs over the WAN.

The secondary RPAs process the data and replicate it to their respective Journal volumes.

This distribution of workload allows the DCG to handle higher throughput and IOPS rates than a single RPA could manage1.

It’s important to note that while there is additional traffic on the WAN, this does not necessarily mean that the FC (Fibre Channel) links or management network are unaffected.However, the most significant increase in traffic is observed on the WAN network, which is the communication link between the RPAs in a DCG configuration1.

To identify whether physical or virtual RPAs are in use on a specific cluster using Unisphere for RecoverPoint, follow these steps:

Navigate to RPA Clusters: In Unisphere, locate and click on the ‘RPA clusters’ section.

Select Cluster Name: Find and select the specific cluster you want to investigate.

View RPA Details: Click on the ‘RPAs’ option to view detailed information about the RPAs associated with the selected cluster.

This process will provide you with the necessary information to determine the type of RPAs (physical or virtual) that are being used within the specified cluster1.

The priority level of a Consistency Group in Dell RecoverPoint is used to manage bandwidth allocation among multiple CGs that share the same primary RecoverPoint Appliance (RPA). Here’s how it works:

Priority Level Setting: The priority level is set within the CG’s settings, indicating its importance relative to other CGs.

Bandwidth Allocation: The higher the priority level, the more bandwidth is allocated to that CG when bandwidth is limited.

Resource Management: This setting helps ensure that critical CGs receive the necessary resources for replication, especially during peak times or when system resources are constrained.

Replication Efficiency: By managing bandwidth allocation through priority levels, RecoverPoint can maintain efficient replication and meet Recovery Point Objectives (RPOs) for all CGs1.

This feature is particularly important in environments with multiple CGs and limited bandwidth, as it allows administrators to ensure that the most critical data is replicated first1.

1.The production host writes data to the production volumes, but is first intercepted by the splitter. The splitter sends the write data to the RPA.

2.Immediately upon receipt of the write data, the local RPA returns an acknowledgement (ACK) to the splitter.

3.The splitter then writes the data to the production storage volume.

4.The storage system returns an ACK to the splitter upon successfully writing the data to storage.

5.The splitter sends an ACK to the host that the write has been completed successfully