Retype

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By using this capability, you can change the current storage template of a volume to a target storage template. You can change the volume properties like quality of service (QoS), provisioning, service level agreement (SLO), or workload. You can also choose to migrate the volume to another pool specified in the target template.

To perform the retype operation on a volume perform the following steps:
  1. Navigate to Storage > Data volumes (or) Boot volumes.
  2. Select a volume and click Retype. PowerVC validates and lists the target templates where the volume can be retyped or migrated to.
  3. Select either Allow storage assisted migration or Allow generic migration.

    When you select the Allow storage assisted migration option, the volume is migrated if the template of the target storage points to a different pool. For details, see considerations section.

    In a case where the backend storage provider cannot migrate the volume, select Allow generic migration option. A new volume is created with the selected target template. The original volume data is copied to the new volume by using the Fibre Channel connectivity on PowerVC. Make sure that the Fibre Channel connectivity exists between PowerVC and storage. No validation is performed on PowerVC for this option. For more information on the connectivity setup, see the Requirements section of Exporting and importing images topic.

Pending retype capability

The retype feature is enhanced with a two-step process to complete the retype operation.

If the retype operation has any pending operations such as changing I/O groups of in-use volumes, PowerVC places the volumes in the pending retype phase. A Pending retype alert message is displayed in the PowerVC GUI. After you complete the pending operations, such as rescan or rediscover the disk for the VM, you can return to PowerVC GUI to finish the retype operation. To finish the retype operation, select the Finish retype option. This feature is only applicable for Storwize®.

  • The Data volumes and the Boot volumes pages display the following options after you select a volume and click Retype.
    • A Pending retype alert message in the Pending tasks column. The Pending tasks column is an optional column and does not display by default. Use the customization icon to select and display the column on the Data volumes and Boot volumes pages.

      Before you select the Finish Retype option, make sure to run the relevant rescan command on LPAR. For example, run the cfgmgr command for AIX VMs.

    • A Finish Retype option to complete the retype process.
    • A Finish Retype option in the Actions menu.
  • The retype volume completion API is introduced to complete the volume retype. For more information, see Retype validation APIs.

Limitations

Consider the following limitations before you perform a retype operation on a volume.
  • The retype operation is only supported for SVC, Hitachi, and PowerMax storage types. PowerMax SRDF is not supported.
  • For available volumes, you can perform the retype operation by using the Storage-Assisted Migration.
  • For Hitachi, Storwize, and PowerMax, a volume can be migrated without selecting any migration options.
  • The retype operation is allowed for either available or in-use volumes. Some storage types might have restriction for the in-use volumes. Be cautious when retype operation of the in-use volumes is performed. If the retype operation involves changing disk paths (for example, changing I/O group or port groups), the disk might lose access to the old paths. In this case, the disk requires a rescan to regain access to the virtual machine.
  • You cannot perform a retype operation on a volume that is part of a group.
  • You cannot perform a retype operation on a volume that is in-use and has multiattach enabled.
  • Generic migration for in-use volumes is not supported.
  • The retype operation is not supported for base template that is enabled with pool mirroring.
  • The retype operation is supported from base template to replication-enabled template and vice versa on Storwize for Global Mirror and Global Mirror Change Volume.
  • When retype operation is performed from base template to replication-enabled template of Storwize, you can choose to retain the auxiliary volume. To retain the auxiliary volume, enter the following command:
    powervc-config storage svc-retain-aux-vol --enable --restart
  • The retype operation of a volume on Storwize that has a mirror pool to a nonmirror pool or vice versa is not allowed. For such a scenario, only volume copy operation is allowed.
  • If a storage template is not assigned to the volume, a warning message appears to set the template ID. To set the template, you can use the Set storage template option on the user interface. Alternatively, you can set the template by using the following command:
    powervc-config storage set-template
  • The retype operation or migration is not allowed for volumes that have snapshots.
  • PowerVC might prompt an error message if the retype operation or migration is not supported by the storage backend.
  • The retype operation for in-use volumes is not supported in Pure Storage.
  • The following table shows the retype operation support matrix for available volumes in Pure Storage.
    Table 1. Retype operation support matrix for available volumes in Pure Storage
    Source replication Target migration_policy Supported or Not supported
    async base Pure driver retype flow  
    sync base Generic migration flow Not supported
    trisync base Generic migration flow Not supported
    base async Pure driver retype flow  
    base sync Generic migration flow  
    base trisync Generic migration flow  
    async sync Generic migration flow Not supported
    async trisync Generic migration flow Not supported
    sync async Generic flow Not supported
    sync trisync Pure driver retype flow  
    trisync async Generic flow Not supported
    trisync sync Pure driver retype flow  
To list the possible target template for retype operation, PowerVC uses retype-validation API. For more information about the retype-validation APIs, see Retype validation APIs.