How to replicate a file system with TrueCopy

Ops Center Protector User Guide

Version

7.9.x

Audience

anonymous

Part Number

MK-99PRT002-10

ft:lastEdition

2024-12-11

It is assumed that the following tasks have been performed:

The Protector Master software has been installed and licensed on a dedicated node. See Installation Tasks and License Tasks.
The Protector Client software has been installed on the source node where the Hitachi Block LDEV is mounted. Note that the LDEV is actually located on the primary Hitachi Block storage device.
The Protector Client software has been installed on the nodes that will act as proxies for both primary and secondary Hitachi Block storage devices. Note that for a TrueCopy replication, the source and destination LDEVs are located on different devices.
The primary and secondary storage devices have been set up as per the Protector requirements and prerequisites. Refer to Hitachi Block prerequisites.
Permissions have been granted to enable the Protector UI, required activities and participating nodes to be accessed. In this example all nodes will be left in the default resource group, so there is no need to allocate nodes to user defined resource groups. Refer to How to configure basic role based access control.

This task describes the steps to follow when protecting data that resides on a file system created on an LDEV allocated from a Hitachi Block storage device. A TrueCopy hardware replication of the P-VOL is created as an S-VOL residing within a different storage device. For more information, refer to About TrueCopy replication. The data flow and policy are as follows:

Figure. TrueCopy Replication Data Flow

Table. Path Replication Policy
Classification Type	Parameter	Value
Path	Include	E:\testdata (E: is where the Hitachi Block LDEV is mounted)

Operation Type	Parameter	Value	Assigned Nodes
Replicate	Refresh Options	Select a schedule for ‘Refresh on schedule’	OS Host, Secondary Hitachi Block Device

Locate the source node in the Nodes Inventory and check that it is authorized and online. This node is where the primary LDEV to be replicated is mounted.
For a file system replication using a Path classification, a basic OS Host node is required. It is not necessary to create the source node in this case since all Protector client nodes default to this type when installed. See How to authorize a node.
Locate the nodes in the Nodes Inventory that will control the primary and secondary Hitachi Block Devices via CMD (Command Device) interfaces and check that they are authorized and online.
These nodes are used by Protector to orchestrate replication of the primary LDEV to the secondary and are identified as the Proxy Node when creating the primary and secondary Hitachi Block Device nodes in the next step. These nodes are known as ISM nodes. The ISM nodes do not appear in the data flow.
Create new primary and secondary Hitachi Block Device nodes (unless ones already exists) using the Hitachi Block Device Node Wizard and check that they are authorized and online.
The Hitachi Block Device node type is grouped under Storage in the Node Type Wizard. See How to add a node and How to authorize a node.The secondary Hitachi Block Device node appears in the replication data flow as the destination node. The primary Hitachi Block Device node is represented in the data flow by the OS Host node where the primary LDEV is mounted.
Define a policy as shown in the table above using the Policy Wizard. See How to create a policy
1. Define a Path classification using the Path Classification Wizard.
  The a Path classification is grouped under Physical in the Policy Wizard.
2. Define a Replicate operation using the Replicate Operation Wizard.
  When an application is used to automatically select the PVOLs used in this continuous replication a trigger schedule can be defined that invokes the application to re-evaluate the PVOLs involved.
Draw a data flow as shown in the figure above using the Data Flow Wizard, that shows the OS Host source node connected to the secondary Hitachi Block Device via a Continuous mover.
TrueCopy is a remote replication technology, so the Hitachi Block Device node shown on the data flow is the where the destination secondary volume (S-VOL) is located. See How to create a data flow.
Assign the Path-Replicate policy to the OS Host source node.
See How to apply a policy to nodes on a data flow.
Assign the Replicate operation to the Hitachi Block Device node.
The Hitachi Block Replication Configuration Wizard is displayed.
Set the replication type to Synchronous Remote Clone, then choose a Pool from one of the available Dynamic Pools. Leave the remaining parameters at their default settings and click OK.
Compile and activate the data flow, checking carefully that there are no errors or warnings.
See How to activate a data flow.
Locate the active data flow in the Monitor Inventory and open its Monitor Details.
The policy will be invoked automatically to create and then maintain the replication according to the policy.
Watch the active data flow via the Monitor Details to ensure the policy is operating as expected.
For a healthy data flow you will periodically see:
- An initial replication job appearing in the Jobs area below the data flow that cycle through stages and ending in Progress - Completed.
- Information messages appearing in the Logs area below the data flow indicating rules activation, storage handler and sequencer events.
- Attachments to storage handler log events confirming which volumes are being replicated.
For a problematic data flow you may see:
- Permanent Node Status icons appear over nodes and associated warning messages displayed to the right of the data flow area.
- Backup jobs appearing in the Jobs area below the data flow that cycle through stages and terminating in Progress - Failed.
- Warning and error messages appearing in the Logs area below the data flow indicating failed events.
Review the status of the Hitachi Block Device via the relevant Hitachi Block Device Details and replications via the Hitachi Block Replications Inventory, to ensure the replication is being created and maintained.
Hitachi Block Devices require ongoing surveillance to ensure that they are operating correctly and sufficient resources are available to store your data securely. See How to view the status of a Hitachi Block storage device.

The replication process can be paused and resumed from here if required.

A TrueCopy replication will appear in the Hitachi Block Replications Inventory and will be updated as and when writes to the primary are made.