Creating an image-mode volume using the CLI

You can use the command-line interface (CLI) to import storage that contains existing data and continue to use this storage. You can also use the advanced functions, such as Copy Services, data migration, and the cache. These disks are known as image-mode volumes.

About this task

Make sure you are aware of the following information before you create image-mode volumes:
  1. Unmanaged-mode managed disks (MDisks) that contain existing data cannot be differentiated from unmanaged-mode MDisks that are blank. Therefore, it is vital that you control the introduction of these MDisks to the clustered system by adding these disks one at a time. For example, map a single LUN from your RAID storage system to the clustered system and refresh the view of MDisks. The newly detected MDisk is displayed.
  2. Do not manually add an unmanaged-mode MDisk that contains existing data to a parent pool. If you do, the data is lost. When you use the command to create an image-mode volume from an unmanaged-mode disk, select the parent pool where it should be added. Ensure that the pool that is selected is not a child pool. Child pools are created from existing pools, called parent pools, and get capacity from the parent pool, not MDisks.

Complete the following steps to create an image-mode volume:

Procedure

  1. Stop all I/O operations from the hosts. Unmap the logical disks that contain the data from the hosts.
  2. Create one or more storage pools. Ensure that the pool is not a child pool.
  3. Map a single array or logical unit from your RAID storage system to the clustered system. You can do this through a switch zoning or a RAID storage system based on your host mappings. The array or logical unit appears as an unmanaged-mode MDisk to the system.
  4. Issue the lsmdisk command to list the unmanaged-mode MDisks.
    If the new unmanaged-mode MDisk is not listed, you can complete a fabric-level discovery. Issue the detectmdisk command to scan the Fibre Channel network for the unmanaged-mode MDisks.
    Note: The detectmdisk command also rebalances MDisk access across the available storage system device ports.
  5. Convert the unmanaged-mode MDisk to an image-mode volume.
    Note: If the volume that you are converting maps to a flash drive, the data that is stored on the volume is not protected against Flash drive failures or node failures. To avoid data loss, add a volume copy that maps to an Flash drive on another node.
    Issue the mkvdisk command to create an image-mode volume object.
  6. Map the new volume to the hosts that were previously using the data that the MDisk now contains. You can use the mkvdiskhostmap command to create a new mapping between a volume and a host. This makes the image-mode volume accessible for I/O operations to the host.

Results

After the volume is mapped to a host object, the volume is detected as a disk drive with which the host can complete I/O operations.

What to do next

If you want to virtualize the storage on an image-mode volume, you can transform it into a striped volume. Migrate the data on the image-mode volume to managed-mode disks in another storage pool. Issue the migratevdisk command to migrate an entire image-mode volume from one storage pool to another storage pool. Ensure that the storage pool that you migrate the image-mode volume to is not a child pool.
Related reference:
mkvdisk