The non-disruptive block import requires installing a host plug-in for a seamless import to PowerStore. The host plug-in enables the orchestrator to communicate with the host multipath software to perform import operations. The combination of native functionality with the host plug-in automates many manual operations that take place during migration. For example, the system automatically completes mapping the hosts, creating the storage resources, and checking the validation.
Non-disruptive 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.
- 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.
- iSCSI and Fibre Channel (FC) are supported for the data transfer between the source storage system and PowerStore. If the backend import connection is FC, the frontend host connection must also be FC. If the backend import connection is iSCSI, the frontend host 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:
- Multipath IO (MPIO) software—either EqualLogic Multipath I/O (EQL MPIO) or native MPIO—must be configured on the source LUNs, volumes, or consistency group. Once the MPIO is set, a host plug-in must be installed (or upgraded if using EQL MPIO). A reboot might be required. We recommend performing the installation along with any required software upgrade of the client operating system.
Non-disruptive terminology
The following table provides definitions for some of the terms that are used in the non-disruptive import section.
Table 2. Non-disruptive 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 |
Non-disruptive import workflow
This section describes a high-level overview of the import workflow.
Step 1: Setup
Perform the following actions before importing storage resources:
- Configure zoning for the front-end connectivity between the client and the PowerStore system (if required).
- Configure the back-end connectivity:
- If using iSCSI, add iSCSI connectivity between the source system and PowerStore system (if not present).
- If using Fibre Channel (FC), configure connectivity and zoning between the source system and the PowerStore system.
- Install the host plug-in in each of the clients that requires access to the data during the import. This ensures that the import is non-disruptive. A reboot might be required as part of the installation of the host plug-in. PowerStore supports three types of host operating systems for the host plug-in: Linux, Microsoft Windows, and VMware. Refer to the PowerStore simple support matrix for the latest details.
Figure 4. Non-disruptive setup
Step 2: Import
Perform the following actions to run the import process:
- Add the source system to PowerStore Manager.
- 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 import types.
- Select Volumes: Enables selecting the source resources, either as volumes or volume groups, to be imported.
- Add to Volume Group (Optional): Enables grouping the source resources into an existing volume group or to a new volume group.
- Map Hosts: Allows selection of the Add hosts (with the Host Plugin configured) for non-disruptive import option to enable adding the clients in which the user has already configured the host plug-in.
- Verify Host Mapping: Validates the host mapping between the selected source resources and the added hosts.
- 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 Import button to start or schedule the import.
- Click the Import button, and the system performs the following actions:
- An import session is created.
- The system requests to the host plug-in a path flip, making the paths from the client to the source system inactive. The system also activates the paths from the client to the PowerStore system.
- A background copy of the data from the source system to the PowerStore system starts. Any new writes from the clients are made to PowerStore and forwarded to the source system to ensure rollback.
Figure 5. Non-disruptive 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), which completes the following steps:
- The paths from the client to the source system are removed.
- The background copy and the forwarding of writes stops.
- Once the systems cut over, there is no rollback.
Figure 6. Non-disruptive cutover
Host plug-ins
There are different operating systems on which the host plug-in can be installed. For details about installing the host plug-in and the full list of supported operating systems and versions, see the document Importing External Storage to PowerStore Guide at Dell.com/powerstoredocs. The host plug-in installation files are available on Dell Support.