PowerStoreOS 1.0.3 added support for agentless block import. The agentless import does not require installing a host plug-in. The orchestrator communicates with the source storage system to coordinate and manage the host mappings. This import type requires a disruptive window as part of the path flip to PowerStore.
Agentless import requirements
The following requirements must be met before migrating to PowerStore:
- The source system must be in a good state and not running a software upgrade.
- The software or operating environment (OE) version for the source system must be supported.
- See the document Importing External Storage to PowerStore Guide on Dell.com/powerstoredocs.
- A software upgrade may be required before starting the import.
- The following front-end connectivity is required:
- Connectivity between the client and source system, and the client and PowerStore can be either iSCSI or Fibre Channel (FC).
- For FC, zoning may be required.
- The following back-end connectivity is required:
- iSCSI and Fibre Channel (FC) are supported for the data transfer between the source storage system and PowerStore. If the backend connection is FC, the frontend connection must also be FC. If the backend connection is iSCSI, the frontend connection can be either FC or iSCSI.
- Before PowerStoreOS 3.0, only iSCSI was available for the data transfer between the source storage system and PowerStore.
- PowerStoreOS 3.0 and higher added Fibre Channel (FC) support for the data transfer between the source and PowerStore system.
- MPIO and host plug-in:
- A host plug-in is not required.
Agentless import terminology
The following table provides definitions for some of the terms that are used in the agentless block import section.
Table 3. Agentless block import terminology
Cutover | Final step in setting the destination system as the primary with no option to cancel (rollback) to the source system |
Cancel | Action of stopping the import, removing any progress that has been completed, and rolling back to the primary storage system |
Path flip | Action of changing the active paths from the client to the source system to the PowerStore system |
Agentless import workflow
This section describes a high-level overview of the agentless import workflow.
Step 1: Setup
Perform the following actions before importing storage resources:
- Configure zoning for the front-end connectivity between the client and PowerStore (if required).
- Add iSCSI connectivity between the source system and PowerStore (if not present). This action enables PowerStore to automatically map itself as an iSCSI host in the source system.
Figure 7. Agentless setup
Step 2: Import
Complete the following steps to perform the import:
- Add the host clients that are accessing the source data to PowerStore Manager from Compute > Hosts & Host Groups.
- Add the source system to PowerStore Manager from Migration > Import External Storage.
- To create an import session, select the added source system and click the Import Storage button which steps through the following:
- Overview: Provides details of the two types of imports available.
- Select Volumes: Allows selection of the source storage resources to import: LUNs, volumes, or consistency groups.
- Add to Volume Group (Optional): Enables grouping the source resources into an existing volume group or to a new volume group.
- Map Hosts: Selecting Map hosts on PowerStore for agentless import enables mapping the clients in which the data is being accessed from.
- Set Import Schedule: Sets when the import begins, either immediately or at a set date and time. This step includes the option to set an automatic cutover.
- Assign Protection Policy (Optional): Assigns the existing protection policy in PowerStore to the source resource after the import completes.
- Review: Shows a summary of the selected options, gives the option to review the source array assigned policies, and shows the Begin Import button to start or schedule the import.
- When you click the Begin import button, the system takes the following actions:
- An import session is created. The state changes from In Progress to Ready to Enable Destination Volume with the source volume as read/write.
- Unmount the source volume on the hosts. The import operation is disruptive to the host I/O access.
- Select More Actions > Enable Destination Volume.
i Confirm that the host application has been stopped or taken offline.
ii Either allow the system to remove the mapping between the hosts and the source resource or perform this step manually.
iii The source volumes go into a read-only state, and hosts are unmapped from the source system.
iv Click the Enable Destination Volume button.
- When the import session is in a Ready to Start Copy state, select the Start Copy option.
i Rescan the host to discover the destination volume and mount the destination volume on the host, making the volume a read/write state. Now the host I/O access is restored.
ii A background copy of the data from the source system to the PowerStore system starts.
iii The import session state changes to Copy In Progress.
iv Any new writes are made to PowerStore and forwarded to the source system to ensure rollback.
Figure 8. Agentless import
Step 3: Cutover
A cutover is allowed when the import session is in a Ready to Cutover state (the source system and PowerStore are synchronized).
- The paths from the client to the source system are removed.
- The background copy and the forwarding of writes stops.
- When the import session is cut over, there is no rollback.
Figure 9. Agentless cutover