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.
Make sure you are aware of the following information
before you create image-mode
volumes:
- 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.
- 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:
- Stop all I/O operations from the hosts. Unmap the logical
disks that contain the data from the hosts.
- Create one or more storage pools.
Ensure that the pool is not a child pool.
- 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.
- 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.
- 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.
- 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.
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.
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.