Migrating a storage partition

About this task

IBM Storage FlashSystem supports the non-disruptive migration of storage partitions between systems. This enables a partition to be migrated from source to the target IBM Storage FlashSystem without any application downtime. You can now perform the storage partition migration in IBM Storage Insights with ease. The migration procedure requires connectivity between the source and target IBM Storage FlashSystem.

Important:

Partition migration from IBM Storage Insights is only supported for the storage systems that are part of FlashSystem grid.
Storage partition migration is available only for the IBM Storage FlashSystem 8.7.0 or later.
- For IBM Storage FlashSystem devices with version 8.7.0 or later, but earlier than 9.1.0, the partition migration is allowed only when the target storage system has fewer than four storage partitions.
- For IBM Storage FlashSystem devices with version 9.1.0 or later, the partition migration is allowed only when the target storage system has fewer than 32 storage partitions.
Before performing a storage partition migration by using IBM Storage Insights, following key permission levels need to be established:
1. System-level access for IBM Storage Insights: The storage administrator must grant IBM Storage Insights access to the source and target IBM Storage FlashSystem systems.
2. User permissions within IBM Storage Insights: A new partition management permission needs to be enabled for each user within IBM Storage Insights who is performing migration tasks. By default, this permission is disabled.
3. You must be having Admin or Monitor role in the IBM Storage Insights to perform storage partition migration.
For more information about enabling the partition management permission, see Manage additional privileges.
If a storage partition is already undergoing migration, initiating a new migration for the same partition is not allowed.

Migration enables relocation of storage partitions from a source system to a target system location. As a consequence of which, the following flow of events occurs:

The resources that are associated with the storage partition such as volumes, volume groups, and host mappings are relocated to the specified storage system location. For more information, see Data migration
The active management system and preferred management systems point to the migrated storage partition.

Following are some common scenarios where you might choose to migrate storage partitions:

When upgrading system hardware from older systems to newer ones.
Load-balancing by migrating storage partitions from overloaded systems to other systems.
Data centre environment or use-case specific scenarios that require storage partition migrations from a source system to a specified target system.

Important: Storage partition migration is available only for the IBM Storage FlashSystem 8.7.0 or later.

Procedure

Go to the Storage partitions page by any one of the following ways:
- Click Main menu, expand Inventory in the left navigation panel, and click Storage systems. The storage systems tabular page is displayed. Click the specific FlashSystem Grid name in the Storage systems column to go to FlashSystem Grid overview page. Then, click Storage partitions in the left navigation panel.
- From the storage system details page, click Storage partition in the left navigation panel. The details of the storage partitions associated with the specific storage system are displayed.
Click the vertical dots menu at the end of each partition, and select Migrate partition.
- Alternatively, you can also select the radio button for a storage partition in the tabular view and click the Migrate now in the blue bar.
Read the informational message about migration overview and click Next.
Optional: Click Edit forecasting time to set the desired past and future dates to determine the capacity growth and workload placement analysis. Then, click Apply changes. The list of compatible storage systems is displayed.
You can set a past date up to 2 years before the current date and a future date up to three years ahead.
Optional: Enable the Show compatibility score toggle icon to generate the compatibility score for the target storage system.
The compatibility score is an AI-generated numerical value (ranging from 1 to 5) that indicates the best-matched storage system for a specified storage partition. Enabling the toggle initiates the AI evaluation to generate the score. Click the AI icon next to Show compatibility score to view details about the calculation.
Optional: Click View evaluation parameters to view the time frame for the workload placement analysis and the partition details.
Optional: Click the score in the Compatibility column to view detailed charts for key parameters, such as capacity, IOPS, data rate, latency, and CPU utilization, along with their fitment scores.
Review the compatible storage systems list based on the compatibility score and select a target storage system to proceed for partition migration and click Next.
Review the migration summary like the source and target storage system, volumes, volume groups, and hosts. If you need to change the previously selected values click Back. When you reviewed the migration summary, click Begin migration
Important:
- An IBM Storage FlashSystem can only support a single storage partition migration in an active state at any given time.
- IBM Storage Insights facilitates these migrations through Call Home with cloud services, ensuring secure and reliable command execution. Storage partition migration is not supported if the storage systems are monitored through the data collector.
- IBM Storage Insights does not perform migration on its own. When you submit a migration request, IBM Storage Insights sends it to IBM Storage FlashSystem through Call Home with cloud services to initiate the migration. IBM Storage Insights updates the migration status only after IBM Storage FlashSystem acknowledges the request. Similarly, IBM Storage FlashSystem does not display a partition migration until it receives and processes the request. When IBM Storage FlashSystem accepts the migration request, IBM Storage Insights displays the partition migration status as In progress.

Results

A migration task is created successfully and you are informed through a notification. Click View details in the notification to see the status of partition migration. You can track the migration task by clicking the task icon in the Dashboards page.

Note:

The migration progress is part of the probe process. Therefore, the migration state will only be updated if the mini probe and full probe are working.
The task is automatically created in IBM Storage Insights even if there is an active migration in the IBM Storage FlashSystem which is not necessarily initiated in the IBM Storage Insights.

You can also track the status of the ongoing migration from the following places in the IBM Storage Insights GUI:

Click View details in the migration task notification.
In the storage system listing page, click the value in the Active migration column.
In the FlashSystem grid page, click the value in the Migration Status column in the Partition migration summary table.
In the Storage Systems page which is present at the left pane of the FlashSystem grid view, click the value in the Active migration column.
In the Storage Partitions page which is present at the left pane of the FlashSystem grid view, click the value in the Migration Status column.

What to do next

Actions to be performed after initiating the migration

When you initiate the storage partition migration in IBM Storage Insights, following actions need to be taken from you during the course of migration:

Important: IBM Storage Insights does not directly connect with IBM Storage FlashSystem to perform the following actions. The commands to perform the migration actions are sent by IBM Storage Insights to IBM Storage FlashSystem through Call Home with cloud services. Call Home with cloud services is then responsible for queuing the commands to IBM Storage FlashSystem to perform migration actions.

Abort Migration: If you need to cancel the partition migration in any case, perform the following action. From the FlashSystem grid view, Click the In progress value in the Migration Status column in the Partition migration summary table. Then click Abort Migration.
Resume: From the FlashSystem grid view, click the User action required value in the Migration Status column in the Partition migration summary table. Then click Resume.
When you perform the resume action, a request is sent to IBM Storage FlashSystem through Call Home with cloud services from IBM Storage Insights to resume migration after confirming that the host paths are valid for the new target storage system.
Note:
- Until the resume action, preferred management location (PML) bookmark is displayed on the source storage system. After completing the resume action, the PML bookmark is displayed on the target system.
- Ensure that there are iSCSI logins or paths available from the host application to the new target before taking Resume action. This connection is to ensure that the new target can receive application I/O when it is made the active management node for the partition. This requirement is also communicated during the Resume action message.
- During the migration process, the buttons for Resume and Abort Migration are displayed together in the migration status sheet. This occurs when the migration reaches a stage where your intervention is required to manually verify that the mapped host is visible to the target system to enable I/O operations. Click Resume to proceed with the migration process. However, you won’t be able to perform both actions simultaneously.
Rollback: From the FlashSystem grid view, Click the User action required value in the Migration Status column in the Partition migration summary table. Then click Rollback.
The storage partition will be rolled back from the target to the source storage system, and PML bookmark shifts to the source storage system. If you rollback, the Resume and Abort action buttons are again visible.
Confirm: Confirm action is only available for the non-automated host (host path validation is needed manually for the target system). When you perform confirm action, host validation is done where you verify that the mapped host is visible to the target storage system to enable I/O operations. The confirm action is skipped for the automated hosts where host path validation is done automatically for the target storage system.
Commit: From the FlashSystem grid view, Click the User action required value in the Migration Status column in the Partition migration summary table. Then click Commit.
Note: During the migration process, the buttons for Rollback and Commit are displayed together in the migration status sheet. This typically occurs when the migration reaches a stage where your intervention is required to clean up the storage partition on the source system or roll back the migrated partition to the source storage system. However, you won't be able to perform both actions simultaneously.

When you perform the commit action, a request is sent to IBM Storage FlashSystem through Call Home with cloud services from IBM Storage Insights to clean up the storage partition on the source system.
Fix Error: If migration is suspended due to some errors in the IBM Storage FlashSystem, Click the Migration error value in the Migration Status column in the Partition migration summary table. Then click Fix Error.
When you click Fix Error, you will get a prompt to open the IBM Storage FlashSystem in a separate tab for troubleshooting the errors in it. Open the IBM Storage FlashSystem and take necessary actions to fix the errors. Come back to IBM Storage Insights and acknowledge the actions taken on the IBM Storage FlashSystem. Once acknowledged, the migration resumes.
Important: When you navigate out of IBM Storage Insights to IBM Storage FlashSystem, you must have access to IBM Storage FlashSystem network. If not, you will get an error as Page not found.

Migration across firmware versions of the storage systems:

Source system on a lower version and target system on a higher version: When the source system is on a version earlier than 8.7.2, and the target system is on version 8.7.2 or later, the following scenarios can occur:
- The host rescan action is initiated at the source system and completes successfully, with host paths accessible from the source. In this case, the next action is Commit.
- The host rescan action is initiated at the source system but fails because hosts or logins are not healthy. In this scenario, a new host rescan action is triggered at the target system. After the host paths are accessible from the target, the option to Commit migration becomes available.
Source system on a higher version and target system on a lower version: When the source system is on version 8.7.2 or later, and the target system is on a version earlier than 8.7.2, A data migration process (DMP) error is raised at the source system. When you resolve the error, the preferred management location (PML) switches to the target system, and the option to Commit migration becomes available.

Monitoring the migration status

When you initiate a storage partition migration, the status displayed in IBM Storage Insights will update to reflect the current stage of the process. Here's a breakdown of the possible status indicators:

In progress: This status signifies that the initial migration commands have been sent to the target IBM Storage FlashSystem and the migration process has begun.
User action required: This status appears specifically during the Resume and Commit stages of the migration. It indicates that your intervention is necessary to complete these critical actions.
Aborting: This status is displayed when you choose to cancel a migration in progress.

The specific status displayed in the Migration Status column of the partition table in the Storage Partitions page might differ slightly depending on the action being performed.