How to replicate an Hitachi Block LDEV with ShadowImage

Ops Center Protector User Guide

Version

7.7.x

Audience

anonymous

Part Number

MK-99PRT002-08

ft:lastEdition

2023-10-26

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 destination node that will act as a proxy for the Hitachi Block storage device. Note that for a ShadowImage replication, the source and destination LDEVs are located on the same device.
The storage device has 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 an LDEV allocated from a Hitachi Block storage device. This is useful when Protector has no way of interacting with the application or OS that is using the LDEV. The replication will be crash consistent, because Protector is not able to orchestrate the replication operation in conjunction with applications using the LDEV. A ShadowImage hardware replication of the P-VOL is created as an S-VOL residing within the same storage device. For more information, refer to About ShadowImage replication. The data flow and policy are as follows:

Figure. ShadowImage Replication Data Flow

Table. Hitachi Block Replication Policy
Classification Type	Parameters	Value
Hitachi Block	Specify additional selections	Selected
Hitachi Block	Logical Devices	10323/10

Operation Type	Parameter	Value	Assigned Nodes
Replicate	Run Options	Run on Schedule (See below)	Hitachi Block Device (source), Hitachi Block Device (destination)
Replicate	Quiesce...	Not selected

Schedule Item Type	Parameter	Value	Policy Operations
Trigger	Days	Select All	Replicate (See above)
	Weeks	Select All
	Time	Scheduled Time
	Start Time	15:00
	Duration	00:00

Locate the node in the Nodes Inventory that will control the Hitachi Block Device via a CMD (Command Device) interface and check that it is authorized and online.
This node is used by Protector to orchestrate replication and is identified as the Proxy Node when creating the Hitachi Block Device node in the next step. This node is known as an ISM node. The ISM node does not appear in the data flow.
Create a new Hitachi Block Device node (unless one already exists) using the Hitachi Block Device Node Wizard and check that it is authorized and online. This node is where the production LDEV to be replicated is located.
For a replication using an Hitachi Block classification, an Hitachi Block Device node is required.

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. This node appears in the replication data flow as both the source and the destination node.
Define a policy as shown in the table above using the Policy Wizard. See How to create a policy
1. Define an Hitachi Block classification using the Hitachi Block Classification Wizard.
  The Hitachi Block classification is grouped under Physical in the Policy Wizard.
2. Define a Replicate operation using the Replicate Operation Wizard.
  In this example, ShadowImage replication will run as a batch operation based on a Trigger schedule. Continuous ShadowImage could also be implemented by using a continuous mover on the dataflow.
3. Define a Trigger schedule using the Schedule Wizard; accessed by clicking on Manage Schedules.
  See How to create a schedule.
Draw a data flow as shown in the figure above using the Data Flow Wizard, that shows the Hitachi Block Device source node connected to the same Hitachi Block Device via a Batch mover.
ShadowImage is an in-system replication technology, so the Hitachi Block Device node is where both the source (P)VOL) and destination (S)VOL) volumes are located. See How to create a data flow.
Assign the Block-Replicate policy to the Hitachi Block Device source node.
See How to apply a policy to nodes on a data flow.
Assign the Replicate operation to the Hitachi Block Device destination node.
The Hitachi Block Replication Configuration Wizard is displayed.
Set the replication type to In System 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.
Note: If the Quiesce configured applications before backup option was not deselected in the Replicate Operation Wizard, then a compiler warning message will be generated because Protector will not be able to quiesce applications using the LDEV.
Locate the active data flow in the Monitor Inventory and open its Monitor Details.
The policy will be invoked automatically to create a replication according to the schedule specified in the policy. The policy can also be manually triggered from the source node in the monitor data flow.
Note: No replication will be created until it is first triggered manually or by the schedule.
See How to trigger an operation from an active data flow.
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:
- Replication jobs 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 refreshed.
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 new ShadowImage replication will appear in the Hitachi Block Replications Inventory and be updated periodically as dictated by the schedule for the policy operation. The previous replication will be overwritten upon each refresh.