Solutions Enabler 9.1 introduces the NDM Update feature to help automate the process of moving applications across arrays requiring a short application downtime.
Benefits of using NDM Update include the following:
- Allows application migration for the following:
- From a VMAX (5876) array to a VMAX3 (5977), VMAX All Flash (5978), or PowerMax (5978) array
- From a VMAX3 (5977) array to a VMAX All Flash (5978) or PowerMax (5978) array
- Supports application (SG) level migration for open systems (FBA devices)
- Is built on existing NDM and SRDF technologies:
- Provides the same streamlined user experience
- Supports pre-sync data between arrays and then schedule downtime to do the cutover.
- Supports spoofing or not spoofing the LUN identity
- Requires minimal disruption of the host I/O:
- Host application is briefly shut down when moving the host visibility to the target.
- Application disruption time limited to its reboot time if spoofing is used.
- Application disruption time limited to its reboot and LUN repointing time if no spoofing is used.
- Carries over existing NDM interoperability with array features to NDM Update, with all existing NDM interactions with LREP and SRDF remaining the same
- Provides the following capabilities:
- Covers all host environments for open systems (FBA devices)
- Addresses host environments where NDM is not supported but a high level of orchestration is preferred
- Enables a high level of orchestration and ease of use
- Has a similar workflow as NDM
- Provides the same support for easy recovery of failed operations
- Provides the same support for the easy cancellation of an ongoing migration
- Maintains DR throughout migration
- Places no additional hardware in the data path
- Compresses data during migration to VMAX All Flash or PowerMax
- Leverages SRDF/s or SRDF/Adp for data transfer
- Is native to HYPERMAX OS with no license required (no SRDF license required)
For the latest connectivity information, refer to the support matrix.
NDM Update operations
Migrating an application from a source to a target array proceeds with a sequence of user-initiated operations, each fully automated. Using Solutions Enabler 9.1, the following operations are undertaken using the symdm library similar to NDM.
When initiating an NDM Update session, the create -offline parameter is used. Similarly, if using Unisphere for PowerMax, select the offline checkbox. See the walkthrough sections for examples of the following operations:
- Migration environment setup: This operation configures the migration environment required to migrate any application from the source array to the target array.
One or more applications can be migrated serially or in parallel from the source to the target array using the migration environment:
- create -offline: This operation examines a specific application’s storage on the source array and automatically provisions equivalent storage on the target array. Source and target devices are configured in a mode that starts copying the data to the target devices.
- -move_identity: This option assigns the target devices the identity of the source devices. If -move_identity is not selected, host applications need to be directed to the new target volumes prior to rebooting the application. This is not the case if move_identity is selected, much like NDM whereby the host sees what it perceives as the original volumes but with a spoofed WWN. (See the relevant NDM section for more information about WWN manipulation.)
- -precopy: This option modifies when the user must shut down the application to allow the source devices to be available during the time the data is copied to the target devices.
- Without the -precopy option, the user must shut down the application before the create -offline command is given. The command will make the target devices visible to the host and the source devices host_inactive.
- With the -precopy option, the command will not make the target devices visible to the host and the application can continue running only on the source array while the data is copied to the target. A migration 'cutover operation is required to continue the migration. The cutover operation makes the target devices visible to the host and the source devices host_inactive.
- The migration cutover operation is only used in the CutoverReady state and requires the user to shut down the application before the cutover command is given.
After a create -offline or the cutover command completes, the administrator must perform a host rescan (or host reboot) and verify that new paths or new LUNs have been discovered prior to restarting the application. Unless the -move_identity option was given, the application configuration would also need to be changed to use the new LUNs.
After the source to target data synchronization is complete and all application data has been migrated to the target array, a commit operation is performed. During a commit operation, Solutions Enabler completes the application migration by releasing resources allocated to perform the migration, which also permanently disables access to the source devices. If the -move_identity option was given during the create -offline command, commit also assigns the identity the target device was created with to the source devices.
- Environment remove: This operation is performed after all migrations have been performed to remove any configuration created by the 'environment setup' operation.
Other supported operations provide means to the following:
- Cancel a migration, removing storage provisioned by Solutions Enabler on the target array, releasing resources allocated to perform the migration, and placing the source devices into the pre-create command state.
- Recover from a failed migration.
- List migration environments, to see an overview of the configured DM environments.
- List migrations to or from a specified array, showing the current status for each.